Author: slebresne
Date: Tue Dec 22 11:29:50 2015
New Revision: 1721361
URL: http://svn.apache.org/viewvc?rev=1721361&view=rev
Log:
Update 3.0 CQL doc following CASSANDRA-10921
Modified:
cassandra/site/publish/doc/cql3/CQL-3.0.html
Modified: cassandra/site/publish/doc/cql3/CQL-3.0.html
URL:
http://svn.apache.org/viewvc/cassandra/site/publish/doc/cql3/CQL-3.0.html?rev=1721361&r1=1721360&r2=1721361&view=diff
==============================================================================
--- cassandra/site/publish/doc/cql3/CQL-3.0.html (original)
+++ cassandra/site/publish/doc/cql3/CQL-3.0.html Tue Dec 22 11:29:50 2015
@@ -1,4 +1,4 @@
-<?xml version='1.0' encoding='utf-8' ?><!DOCTYPE html PUBLIC "-//W3C//DTD
XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html
xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type"
content="text/html; charset=utf-8"/><title>CQL</title></head><body><p><link
rel="StyleSheet" href="CQL.css" type="text/css" media="screen"></p><h1
id="CassandraQueryLanguageCQLv3.3.1">Cassandra Query Language (CQL)
v3.3.1</h1><span id="tableOfContents"><ol style="list-style: none;"><li><a
href="CQL.html#CassandraQueryLanguageCQLv3.3.1">Cassandra Query Language (CQL)
v3.3.1</a><ol style="list-style: none;"><li><a href="CQL.html#CQLSyntax">CQL
Syntax</a><ol style="list-style: none;"><li><a
href="CQL.html#Preamble">Preamble</a></li><li><a
href="CQL.html#Conventions">Conventions</a></li><li><a
href="CQL.html#identifiers">Identifiers and keywords</a></li><li><a
href="CQL.html#constants">Constants</a></li><li><a
href="CQL.html#Comments">Comments</a></l
i><li><a href="CQL.html#statements">Statements</a></li><li><a
href="CQL.html#preparedStatement">Prepared Statement</a></li></ol></li><li><a
href="CQL.html#dataDefinition">Data Definition</a><ol style="list-style:
none;"><li><a href="CQL.html#createKeyspaceStmt">CREATE KEYSPACE</a></li><li><a
href="CQL.html#useStmt">USE</a></li><li><a
href="CQL.html#alterKeyspaceStmt">ALTER KEYSPACE</a></li><li><a
href="CQL.html#dropKeyspaceStmt">DROP KEYSPACE</a></li><li><a
href="CQL.html#createTableStmt">CREATE TABLE</a></li><li><a
href="CQL.html#alterTableStmt">ALTER TABLE</a></li><li><a
href="CQL.html#dropTableStmt">DROP TABLE</a></li><li><a
href="CQL.html#truncateStmt">TRUNCATE</a></li><li><a
href="CQL.html#createIndexStmt">CREATE INDEX</a></li><li><a
href="CQL.html#dropIndexStmt">DROP INDEX</a></li><li><a
href="CQL.html#createMVStmt">CREATE MATERIALIZED VIEW</a></li><li><a
href="CQL.html#alterMVStmt">ALTER MATERIALIZED VIEW</a></li><li><a
href="CQL.html#dropMVStmt">DROP MATERIALIZED VIEW</a></l
i><li><a href="CQL.html#createTypeStmt">CREATE TYPE</a></li><li><a
href="CQL.html#alterTypeStmt">ALTER TYPE</a></li><li><a
href="CQL.html#dropTypeStmt">DROP TYPE</a></li><li><a
href="CQL.html#createTriggerStmt">CREATE TRIGGER</a></li><li><a
href="CQL.html#dropTriggerStmt">DROP TRIGGER</a></li><li><a
href="CQL.html#createFunctionStmt">CREATE FUNCTION</a></li><li><a
href="CQL.html#dropFunctionStmt">DROP FUNCTION</a></li><li><a
href="CQL.html#createAggregateStmt">CREATE AGGREGATE</a></li><li><a
href="CQL.html#dropAggregateStmt">DROP AGGREGATE</a></li></ol></li><li><a
href="CQL.html#dataManipulation">Data Manipulation</a><ol style="list-style:
none;"><li><a href="CQL.html#insertStmt">INSERT</a></li><li><a
href="CQL.html#updateStmt">UPDATE</a></li><li><a
href="CQL.html#deleteStmt">DELETE</a></li><li><a
href="CQL.html#batchStmt">BATCH</a></li></ol></li><li><a
href="CQL.html#queries">Queries</a><ol style="list-style: none;"><li><a
href="CQL.html#selectStmt">SELECT</a></li></ol></li><li><a
href="CQL.html#databaseRoles">Database Roles</a><ol style="list-style:
none;"><li><a href="CQL.html#createRoleStmt">CREATE ROLE</a></li><li><a
href="CQL.html#alterRoleStmt">ALTER ROLE</a></li><li><a
href="CQL.html#dropRoleStmt">DROP ROLE</a></li><li><a
href="CQL.html#grantRoleStmt">GRANT ROLE</a></li><li><a
href="CQL.html#revokeRoleStmt">REVOKE ROLE</a></li><li><a
href="CQL.html#createUserStmt">CREATE USER </a></li><li><a
href="CQL.html#alterUserStmt">ALTER USER </a></li><li><a
href="CQL.html#dropUserStmt">DROP USER </a></li><li><a
href="CQL.html#listUsersStmt">LIST USERS</a></li></ol></li><li><a
href="CQL.html#dataControl">Data Control</a><ol style="list-style:
none;"><li><a href="CQL.html#permissions">Permissions </a></li><li><a
href="CQL.html#grantPermissionsStmt">GRANT PERMISSION</a></li><li><a
href="CQL.html#revokePermissionsStmt">REVOKE
PERMISSION</a></li></ol></li><li><a href="CQL.html#types">Data Types</a><ol
style="list-style: none;"><li><a href="CQL.html#usingtimestamps">W
orking with timestamps</a></li><li><a href="CQL.html#usingdates">Working with
dates</a></li><li><a href="CQL.html#usingtime">Working with time</a></li><li><a
href="CQL.html#counters">Counters</a></li><li><a
href="CQL.html#collections">Working with collections</a></li></ol></li><li><a
href="CQL.html#functions">Functions</a><ol style="list-style: none;"><li><a
href="CQL.html#tokenFun">Token</a></li><li><a
href="CQL.html#uuidFun">Uuid</a></li><li><a
href="CQL.html#timeuuidFun">Timeuuid functions</a></li><li><a
href="CQL.html#timeFun">Time conversion functions</a></li><li><a
href="CQL.html#blobFun">Blob conversion functions</a></li></ol></li><li><a
href="CQL.html#aggregates">Aggregates</a><ol style="list-style: none;"><li><a
href="CQL.html#countFct">Count</a></li><li><a href="CQL.html#maxMinFcts">Max
and Min</a></li><li><a href="CQL.html#sumFct">Sum</a></li><li><a
href="CQL.html#avgFct">Avg</a></li></ol></li><li><a
href="CQL.html#udfs">User-Defined Functions</a></li><li><a href="CQL.htm
l#udas">User-Defined Aggregates</a></li><li><a href="CQL.html#json">JSON
Support</a><ol style="list-style: none;"><li><a
href="CQL.html#selectJson">SELECT JSON</a></li><li><a
href="CQL.html#insertJson">INSERT JSON</a></li><li><a
href="CQL.html#jsonEncoding">JSON Encoding of Cassandra Data
Types</a></li><li><a href="CQL.html#fromJson">The fromJson()
Function</a></li><li><a href="CQL.html#toJson">The toJson()
Function</a></li></ol></li><li><a href="CQL.html#appendixA">Appendix A: CQL
Keywords</a></li><li><a href="CQL.html#appendixB">Appendix B: CQL Reserved
Types</a></li><li><a href="CQL.html#changes">Changes</a><ol style="list-style:
none;"><li><a href="CQL.html#a3.3.1">3.3.1</a></li><li><a
href="CQL.html#a3.3.0">3.3.0</a></li><li><a
href="CQL.html#a3.2.0">3.2.0</a></li><li><a
href="CQL.html#a3.1.7">3.1.7</a></li><li><a
href="CQL.html#a3.1.6">3.1.6</a></li><li><a
href="CQL.html#a3.1.5">3.1.5</a></li><li><a
href="CQL.html#a3.1.4">3.1.4</a></li><li><a href="CQL.html#a3.1.3">3.1.3</a></
li><li><a href="CQL.html#a3.1.2">3.1.2</a></li><li><a
href="CQL.html#a3.1.1">3.1.1</a></li><li><a
href="CQL.html#a3.1.0">3.1.0</a></li><li><a
href="CQL.html#a3.0.5">3.0.5</a></li><li><a
href="CQL.html#a3.0.4">3.0.4</a></li><li><a
href="CQL.html#a3.0.3">3.0.3</a></li><li><a
href="CQL.html#a3.0.2">3.0.2</a></li><li><a
href="CQL.html#a3.0.1">3.0.1</a></li></ol></li><li><a
href="CQL.html#Versioning">Versioning</a></li></ol></li></ol></span><h2
id="CQLSyntax">CQL Syntax</h2><h3 id="Preamble">Preamble</h3><p>This document
describes the Cassandra Query Language (CQL) version 3. CQL v3 is not backward
compatible with CQL v2 and differs from it in numerous ways. Note that this
document describes the last version of the languages. However, the <a
href="#changes">changes</a> section provides the diff between the different
versions of CQL v3.</p><p>CQL v3 offers a model very close to SQL in the sense
that data is put in <em>tables</em> containing <em>rows</em> of
<em>columns</em>. For that reas
on, when used in this document, these terms (tables, rows and columns) have
the same definition than they have in SQL. But please note that as such, they
do <strong>not</strong> refer to the concept of rows and columns found in the
internal implementation of Cassandra and in the thrift and CQL v2 API.</p><h3
id="Conventions">Conventions</h3><p>To aid in specifying the CQL syntax, we
will use the following conventions in this document:</p><ul><li>Language rules
will be given in a <a
href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form";>BNF</a> -like
notation:</li></ul><pre class="syntax"><pre><start> ::= TERMINAL
<non-terminal1> <non-terminal1>
+<?xml version='1.0' encoding='utf-8' ?><!DOCTYPE html PUBLIC "-//W3C//DTD
XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html
xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type"
content="text/html; charset=utf-8"/><title>CQL</title></head><body><p><link
rel="StyleSheet" href="CQL.css" type="text/css" media="screen"></p><h1
id="CassandraQueryLanguageCQLv3.4.0">Cassandra Query Language (CQL)
v3.4.0</h1><span id="tableOfContents"><ol style="list-style: none;"><li><a
href="CQL.html#CassandraQueryLanguageCQLv3.4.0">Cassandra Query Language (CQL)
v3.4.0</a><ol style="list-style: none;"><li><a href="CQL.html#CQLSyntax">CQL
Syntax</a><ol style="list-style: none;"><li><a
href="CQL.html#Preamble">Preamble</a></li><li><a
href="CQL.html#Conventions">Conventions</a></li><li><a
href="CQL.html#identifiers">Identifiers and keywords</a></li><li><a
href="CQL.html#constants">Constants</a></li><li><a
href="CQL.html#Comments">Comments</a></l
i><li><a href="CQL.html#statements">Statements</a></li><li><a
href="CQL.html#preparedStatement">Prepared Statement</a></li></ol></li><li><a
href="CQL.html#dataDefinition">Data Definition</a><ol style="list-style:
none;"><li><a href="CQL.html#createKeyspaceStmt">CREATE KEYSPACE</a></li><li><a
href="CQL.html#useStmt">USE</a></li><li><a
href="CQL.html#alterKeyspaceStmt">ALTER KEYSPACE</a></li><li><a
href="CQL.html#dropKeyspaceStmt">DROP KEYSPACE</a></li><li><a
href="CQL.html#createTableStmt">CREATE TABLE</a></li><li><a
href="CQL.html#alterTableStmt">ALTER TABLE</a></li><li><a
href="CQL.html#dropTableStmt">DROP TABLE</a></li><li><a
href="CQL.html#truncateStmt">TRUNCATE</a></li><li><a
href="CQL.html#createIndexStmt">CREATE INDEX</a></li><li><a
href="CQL.html#dropIndexStmt">DROP INDEX</a></li><li><a
href="CQL.html#createMVStmt">CREATE MATERIALIZED VIEW</a></li><li><a
href="CQL.html#alterMVStmt">ALTER MATERIALIZED VIEW</a></li><li><a
href="CQL.html#dropMVStmt">DROP MATERIALIZED VIEW</a></l
i><li><a href="CQL.html#createTypeStmt">CREATE TYPE</a></li><li><a
href="CQL.html#alterTypeStmt">ALTER TYPE</a></li><li><a
href="CQL.html#dropTypeStmt">DROP TYPE</a></li><li><a
href="CQL.html#createTriggerStmt">CREATE TRIGGER</a></li><li><a
href="CQL.html#dropTriggerStmt">DROP TRIGGER</a></li><li><a
href="CQL.html#createFunctionStmt">CREATE FUNCTION</a></li><li><a
href="CQL.html#dropFunctionStmt">DROP FUNCTION</a></li><li><a
href="CQL.html#createAggregateStmt">CREATE AGGREGATE</a></li><li><a
href="CQL.html#dropAggregateStmt">DROP AGGREGATE</a></li></ol></li><li><a
href="CQL.html#dataManipulation">Data Manipulation</a><ol style="list-style:
none;"><li><a href="CQL.html#insertStmt">INSERT</a></li><li><a
href="CQL.html#updateStmt">UPDATE</a></li><li><a
href="CQL.html#deleteStmt">DELETE</a></li><li><a
href="CQL.html#batchStmt">BATCH</a></li></ol></li><li><a
href="CQL.html#queries">Queries</a><ol style="list-style: none;"><li><a
href="CQL.html#selectStmt">SELECT</a></li></ol></li><li><a
href="CQL.html#databaseRoles">Database Roles</a><ol style="list-style:
none;"><li><a href="CQL.html#createRoleStmt">CREATE ROLE</a></li><li><a
href="CQL.html#alterRoleStmt">ALTER ROLE</a></li><li><a
href="CQL.html#dropRoleStmt">DROP ROLE</a></li><li><a
href="CQL.html#grantRoleStmt">GRANT ROLE</a></li><li><a
href="CQL.html#revokeRoleStmt">REVOKE ROLE</a></li><li><a
href="CQL.html#createUserStmt">CREATE USER </a></li><li><a
href="CQL.html#alterUserStmt">ALTER USER </a></li><li><a
href="CQL.html#dropUserStmt">DROP USER </a></li><li><a
href="CQL.html#listUsersStmt">LIST USERS</a></li></ol></li><li><a
href="CQL.html#dataControl">Data Control</a><ol style="list-style:
none;"><li><a href="CQL.html#permissions">Permissions </a></li><li><a
href="CQL.html#grantPermissionsStmt">GRANT PERMISSION</a></li><li><a
href="CQL.html#revokePermissionsStmt">REVOKE
PERMISSION</a></li></ol></li><li><a href="CQL.html#types">Data Types</a><ol
style="list-style: none;"><li><a href="CQL.html#usingtimestamps">W
orking with timestamps</a></li><li><a href="CQL.html#usingdates">Working with
dates</a></li><li><a href="CQL.html#usingtime">Working with time</a></li><li><a
href="CQL.html#counters">Counters</a></li><li><a
href="CQL.html#collections">Working with collections</a></li></ol></li><li><a
href="CQL.html#functions">Functions</a><ol style="list-style: none;"><li><a
href="CQL.html#tokenFun">Token</a></li><li><a
href="CQL.html#uuidFun">Uuid</a></li><li><a
href="CQL.html#timeuuidFun">Timeuuid functions</a></li><li><a
href="CQL.html#timeFun">Time conversion functions</a></li><li><a
href="CQL.html#blobFun">Blob conversion functions</a></li></ol></li><li><a
href="CQL.html#aggregates">Aggregates</a><ol style="list-style: none;"><li><a
href="CQL.html#countFct">Count</a></li><li><a href="CQL.html#maxMinFcts">Max
and Min</a></li><li><a href="CQL.html#sumFct">Sum</a></li><li><a
href="CQL.html#avgFct">Avg</a></li></ol></li><li><a
href="CQL.html#udfs">User-Defined Functions</a></li><li><a href="CQL.htm
l#udas">User-Defined Aggregates</a></li><li><a href="CQL.html#json">JSON
Support</a><ol style="list-style: none;"><li><a
href="CQL.html#selectJson">SELECT JSON</a></li><li><a
href="CQL.html#insertJson">INSERT JSON</a></li><li><a
href="CQL.html#jsonEncoding">JSON Encoding of Cassandra Data
Types</a></li><li><a href="CQL.html#fromJson">The fromJson()
Function</a></li><li><a href="CQL.html#toJson">The toJson()
Function</a></li></ol></li><li><a href="CQL.html#appendixA">Appendix A: CQL
Keywords</a></li><li><a href="CQL.html#appendixB">Appendix B: CQL Reserved
Types</a></li><li><a href="CQL.html#changes">Changes</a><ol style="list-style:
none;"><li><a href="CQL.html#a3.4.0">3.4.0</a></li><li><a
href="CQL.html#a3.3.1">3.3.1</a></li><li><a
href="CQL.html#a3.3.0">3.3.0</a></li><li><a
href="CQL.html#a3.2.0">3.2.0</a></li><li><a
href="CQL.html#a3.1.7">3.1.7</a></li><li><a
href="CQL.html#a3.1.6">3.1.6</a></li><li><a
href="CQL.html#a3.1.5">3.1.5</a></li><li><a href="CQL.html#a3.1.4">3.1.4</a></
li><li><a href="CQL.html#a3.1.3">3.1.3</a></li><li><a
href="CQL.html#a3.1.2">3.1.2</a></li><li><a
href="CQL.html#a3.1.1">3.1.1</a></li><li><a
href="CQL.html#a3.1.0">3.1.0</a></li><li><a
href="CQL.html#a3.0.5">3.0.5</a></li><li><a
href="CQL.html#a3.0.4">3.0.4</a></li><li><a
href="CQL.html#a3.0.3">3.0.3</a></li><li><a
href="CQL.html#a3.0.2">3.0.2</a></li><li><a
href="CQL.html#a3.0.1">3.0.1</a></li></ol></li><li><a
href="CQL.html#Versioning">Versioning</a></li></ol></li></ol></span><h2
id="CQLSyntax">CQL Syntax</h2><h3 id="Preamble">Preamble</h3><p>This document
describes the Cassandra Query Language (CQL) version 3. CQL v3 is not backward
compatible with CQL v2 and differs from it in numerous ways. Note that this
document describes the last version of the languages. However, the <a
href="#changes">changes</a> section provides the diff between the different
versions of CQL v3.</p><p>CQL v3 offers a model very close to SQL in the sense
that data is put in <em>tables</em> containing <em>
rows</em> of <em>columns</em>. For that reason, when used in this document,
these terms (tables, rows and columns) have the same definition than they have
in SQL. But please note that as such, they do <strong>not</strong> refer to the
concept of rows and columns found in the internal implementation of Cassandra
and in the thrift and CQL v2 API.</p><h3 id="Conventions">Conventions</h3><p>To
aid in specifying the CQL syntax, we will use the following conventions in this
document:</p><ul><li>Language rules will be given in a <a
href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form";>BNF</a> -like
notation:</li></ul><pre class="syntax"><pre><start> ::= TERMINAL
<non-terminal1> <non-terminal1>
</pre></pre><ul><li>Nonterminal symbols will have <code><angle
brackets></code>.</li><li>As additional shortcut notations to BNF, we’ll
use traditional regular expression’s symbols (<code>?</code>,
<code>+</code> and <code>*</code>) to signify that a given symbol is optional
and/or can be repeated. We’ll also allow parentheses to group symbols and
the <code>[<characters>]</code> notation to represent any one of
<code><characters></code>.</li><li>The grammar is provided for documentation
purposes and leave some minor details out. For instance, the last column
definition in a <code>CREATE TABLE</code> statement is optional but supported
if present even though the provided grammar in this document suggest it is not
supported. </li><li>Sample code will be provided in a code block:</li></ul><pre
class="sample"><pre>SELECT sample_usage FROM cql;
</pre></pre><ul><li>References to keywords or pieces of CQL code in running
text will be shown in a <code>fixed-width font</code>.</li></ul><h3
id="identifiers">Identifiers and keywords</h3><p>The CQL language uses
<em>identifiers</em> (or <em>names</em>) to identify tables, columns and other
objects. An identifier is a token matching the regular expression
<code>[a-zA-Z]</code><code>[a-zA-Z0-9_]</code><code>*</code>.</p><p>A number of
such identifiers, like <code>SELECT</code> or <code>WITH</code>, are
<em>keywords</em>. They have a fixed meaning for the language and most are
reserved. The list of those keywords can be found in <a
href="#appendixA">Appendix A</a>.</p><p>Identifiers and (unquoted) keywords are
case insensitive. Thus <code>SELECT</code> is the same than <code>select</code>
or <code>sElEcT</code>, and <code>myId</code> is the same than
<code>myid</code> or <code>MYID</code> for instance. A convention often used
(in particular by the samples of this documentation) is t
o use upper case for keywords and lower case for other
identifiers.</p><p>There is a second kind of identifiers called <em>quoted
identifiers</em> defined by enclosing an arbitrary sequence of characters in
double-quotes(<code>"</code>). Quoted identifiers are never keywords. Thus
<code>"select"</code> is not a reserved keyword and can be used to refer to a
column, while <code>select</code> would raise a parse error. Also, contrarily
to unquoted identifiers and keywords, quoted identifiers are case sensitive
(<code>"My Quoted Id"</code> is <em>different</em> from <code>"my quoted
id"</code>). A fully lowercase quoted identifier that matches
<code>[a-zA-Z]</code><code>[a-zA-Z0-9_]</code><code>*</code> is equivalent to
the unquoted identifier obtained by removing the double-quote (so
<code>"myid"</code> is equivalent to <code>myid</code> and to <code>myId</code>
but different from <code>"myId"</code>). Inside a quoted identifier, the
double-quote character can be repeated to escape it
, so <code>"foo "" bar"</code> is a valid identifier.</p><h3
id="constants">Constants</h3><p>CQL defines the following kind of
<em>constants</em>: strings, integers, floats, booleans, uuids and
blobs:</p><ul><li>A string constant is an arbitrary sequence of characters
characters enclosed by single-quote(<code>'</code>). One can include a
single-quote in a string by repeating it, e.g. <code>'It''s raining
today'</code>. Those are not to be confused with quoted identifiers that use
double-quotes.</li><li>An integer constant is defined by
<code>'-'?[0-9]+</code>.</li><li>A float constant is defined by
<code>'-'?[0-9]+('.'[0-9]*)?([eE][+-]?[0-9+])?</code>. On top of that,
<code>NaN</code> and <code>Infinity</code> are also float constants.</li><li>A
boolean constant is either <code>true</code> or <code>false</code> up to
case-insensitivity (i.e. <code>True</code> is a valid boolean
constant).</li><li>A <a
href="http://en.wikipedia.org/wiki/Universally_unique_identifier";>UUID</a>
constan
t is defined by <code>hex{8}-hex{4}-hex{4}-hex{4}-hex{12}</code> where
<code>hex</code> is an hexadecimal character, e.g. <code>[0-9a-fA-F]</code> and
<code>{4}</code> is the number of such characters.</li><li>A blob constant is
an hexadecimal number defined by <code>0[xX](hex)+</code> where
<code>hex</code> is an hexadecimal character, e.g.
<code>[0-9a-fA-F]</code>.</li></ul><p>For how these constants are typed, see
the <a href="#types">data types section</a>.</p><h3
id="Comments">Comments</h3><p>A comment in CQL is a line beginning by either
double dashes (<code>--</code>) or double slash
(<code>//</code>).</p><p>Multi-line comments are also supported through
enclosure within <code>/*</code> and <code>*/</code> (but nesting is not
supported).</p><pre class="sample"><pre>-- This is a comment
// This is a comment too
@@ -647,4 +647,4 @@ INSERT INTO atable (pk, val) VALUES (3,3
INSERT INTO atable (pk, val) VALUES (4,4);
SELECT average(val) FROM atable;
</pre></pre><p></p><p>See <a href="#createAggregateStmt"><code>CREATE
AGGREGATE</code></a> and <a href="#dropAggregateStmt"><code>DROP
AGGREGATE</code></a>.</p><h2 id="json">JSON Support</h2><p>Cassandra 2.2
introduces JSON support to <a href="#selectStmt"><code>SELECT</code></a> and <a
href="#insertStmt"><code>INSERT</code></a> statements. This support does not
fundamentally alter the CQL API (for example, the schema is still enforced), it
simply provides a convenient way to work with JSON documents.</p><h3
id="selectJson">SELECT JSON</h3><p>With <code>SELECT</code> statements, the new
<code>JSON</code> keyword can be used to return each row as a single
<code>JSON</code> encoded map. The remainder of the <code>SELECT</code>
statment behavior is the same.</p><p>The result map keys are the same as the
column names in a normal result set. For example, a statement like
"<code>SELECT JSON a, ttl(b) FROM ...</code>" would result in a map with keys
<code>"a"</code> and <code>"ttl(b)"</
code>. However, this is one notable exception: for symmetry with <code>INSERT
JSON</code> behavior, case-sensitive column names with upper-case letters will
be surrounded with double quotes. For example, "<code>SELECT JSON myColumn
FROM ...</code>" would result in a map key <code>"\"myColumn\""</code> (note
the escaped quotes).</p><p>The map values will <code>JSON</code>-encoded
representations (as described below) of the result set values.</p><h3
id="insertJson">INSERT JSON</h3><p>With <code>INSERT</code> statements, the new
<code>JSON</code> keyword can be used to enable inserting a <code>JSON</code>
encoded map as a single row. The format of the <code>JSON</code> map should
generally match that returned by a <code>SELECT JSON</code> statement on the
same table. In particular, case-sensitive column names should be surrounded
with double quotes. For example, to insert into a table with two columns named
“myKey” and “value”, you would do the following:</
p><pre class="sample"><pre>INSERT INTO mytable JSON '{"\"myKey\"": 0, "value":
0}'
-</pre></pre><p>Any columns which are ommitted from the <code>JSON</code> map
will be defaulted to a <code>NULL</code> value (which will result in a
tombstone being created).</p><h3 id="jsonEncoding">JSON Encoding of Cassandra
Data Types</h3><p>Where possible, Cassandra will represent and accept data
types in their native <code>JSON</code> representation. Cassandra will also
accept string representations matching the CQL literal format for all
single-field types. For example, floats, ints, UUIDs, and dates can be
represented by CQL literal strings. However, compound types, such as
collections, tuples, and user-defined types must be represented by native
<code>JSON</code> collections (maps and lists) or a JSON-encoded string
representation of the collection.</p><p>The following table describes the
encodings that Cassandra will accept in <code>INSERT JSON</code> values (and
<code>fromJson()</code> arguments) as well as the format Cassandra will use
when returning data for <code>SELE
CT JSON</code> statements (and
<code>fromJson()</code>):</p><table><tr><th>type </th><th>formats accepted
</th><th>return format </th><th>notes</th></tr><tr><td><code>ascii</code>
</td><td>string </td><td>string </td><td>Uses
JSON’s <code>\u</code> character
escape</td></tr><tr><td><code>bigint</code> </td><td>integer, string
</td><td>integer </td><td>String must be valid 64 bit
integer</td></tr><tr><td><code>blob</code> </td><td>string
</td><td>string </td><td>String should be 0x followed by an even
number of hex digits</td></tr><tr><td><code>boolean</code> </td><td>boolean,
string </td><td>boolean </td><td>String must be
“true” or "false"</td></tr><tr><td><code>date</code>
</td><td>string </td><td>string </td><td>Date in
format <code>YYYY-MM-DD</code>, timezone
UTC</td></tr><tr><td><code>decimal</code> </td><td>integer, float,
string</td><t
d>float </td><td>May exceed 32 or 64-bit IEEE-754 floating point
precision in client-side decoder</td></tr><tr><td><code>double</code>
</td><td>integer, float, string</td><td>float </td><td>String must
be valid integer or float</td></tr><tr><td><code>float</code>
</td><td>integer, float, string</td><td>float </td><td>String must
be valid integer or float</td></tr><tr><td><code>inet</code>
</td><td>string </td><td>string </td><td>IPv4 or IPv6
address</td></tr><tr><td><code>int</code> </td><td>integer, string
</td><td>integer </td><td>String must be valid 32 bit
integer</td></tr><tr><td><code>list</code> </td><td>list, string
</td><td>list </td><td>Uses JSON’s native list
representation</td></tr><tr><td><code>map</code> </td><td>map, string
</td><td>map </td><td>Uses JSON’s native map
representation</td></tr><tr><td><code>smallint</cod
e> </td><td>integer, string </td><td>integer </td><td>String
must be valid 16 bit integer</td></tr><tr><td><code>set</code>
</td><td>list, string </td><td>list </td><td>Uses
JSON’s native list representation</td></tr><tr><td><code>text</code>
</td><td>string </td><td>string </td><td>Uses
JSON’s <code>\u</code> character
escape</td></tr><tr><td><code>time</code> </td><td>string
</td><td>string </td><td>Time of day in format
<code>HH-MM-SS[.fffffffff]</code></td></tr><tr><td><code>timestamp</code></td><td>integer,
string </td><td>string </td><td>A timestamp. Strings constant
are allow to input timestamps as dates, see <a href="#usingdates">Working with
dates</a> below for more information. Datestamps with format <code>YYYY-MM-DD
HH:MM:SS.SSS</code> are returned.</td></tr><tr><td><code>timeuuid</code>
</td><td>string </td><td>string </
td><td>Type 1 UUID. See <a href="#constants">Constants</a> for the UUID
format</td></tr><tr><td><code>tinyint</code> </td><td>integer, string
</td><td>integer </td><td>String must be valid 8 bit
integer</td></tr><tr><td><code>tuple</code> </td><td>list, string
</td><td>list </td><td>Uses JSON’s native list
representation</td></tr><tr><td><code>UDT</code> </td><td>map, string
</td><td>map </td><td>Uses JSON’s native map
representation with field names as keys</td></tr><tr><td><code>uuid</code>
</td><td>string </td><td>string </td><td>See <a
href="#constants">Constants</a> for the UUID
format</td></tr><tr><td><code>varchar</code> </td><td>string
</td><td>string </td><td>Uses JSON’s <code>\u</code> character
escape</td></tr><tr><td><code>varint</code> </td><td>integer, string
</td><td>integer </td><td>Variable length; may overflow
32 or 64 bit integers in client-side decoder</td></tr></table><h3
id="fromJson">The fromJson() Function</h3><p>The <code>fromJson()</code>
function may be used similarly to <code>INSERT JSON</code>, but for a single
column value. It may only be used in the <code>VALUES</code> clause of an
<code>INSERT</code> statement or as one of the column values in an
<code>UPDATE</code>, <code>DELETE</code>, or <code>SELECT</code> statement.
For example, it cannot be used in the selection clause of a <code>SELECT</code>
statement.</p><h3 id="toJson">The toJson() Function</h3><p>The
<code>toJson()</code> function may be used similarly to <code>SELECT
JSON</code>, but for a single column value. It may only be used in the
selection clause of a <code>SELECT</code> statement.</p><h2
id="appendixA">Appendix A: CQL Keywords</h2><p>CQL distinguishes between
<em>reserved</em> and <em>non-reserved</em> keywords. Reserved keywords cannot
be used as identifier, they are truly reserved for the language (
but one can enclose a reserved keyword by double-quotes to use it as an
identifier). Non-reserved keywords however only have a specific meaning in
certain context but can used as identifer otherwise. The only <em>raison
d'être</em> of these non-reserved keywords is convenience: some keyword are
non-reserved when it was always easy for the parser to decide whether they were
used as keywords or not.</p><table><tr><th>Keyword </th><th>Reserved?
</th></tr><tr><td><code>ADD</code> </td><td>yes
</td></tr><tr><td><code>AGGREGATE</code> </td><td>no
</td></tr><tr><td><code>ALL</code> </td><td>no
</td></tr><tr><td><code>ALLOW</code> </td><td>yes
</td></tr><tr><td><code>ALTER</code> </td><td>yes
</td></tr><tr><td><code>AND</code> </td><td>yes
</td></tr><tr><td><code>APPLY</code> </td><td>yes
</td></tr><tr><td><code>AS</code> </td><td>no
</td></tr><tr><td><code>ASC</code> </td><td>yes
</td></tr><tr><td><code>ASCII<
/code> </td><td>no </td></tr><tr><td><code>AUTHORIZE</code>
</td><td>yes </td></tr><tr><td><code>BATCH</code> </td><td>yes
</td></tr><tr><td><code>BEGIN</code> </td><td>yes
</td></tr><tr><td><code>BIGINT</code> </td><td>no
</td></tr><tr><td><code>BLOB</code> </td><td>no
</td></tr><tr><td><code>BOOLEAN</code> </td><td>no
</td></tr><tr><td><code>BY</code> </td><td>yes
</td></tr><tr><td><code>CALLED</code> </td><td>no
</td></tr><tr><td><code>CLUSTERING</code> </td><td>no
</td></tr><tr><td><code>COLUMNFAMILY</code> </td><td>yes
</td></tr><tr><td><code>COMPACT</code> </td><td>no
</td></tr><tr><td><code>CONTAINS</code> </td><td>no
</td></tr><tr><td><code>COUNT</code> </td><td>no
</td></tr><tr><td><code>COUNTER</code> </td><td>no
</td></tr><tr><td><code>CREATE</code> </td><td>yes
</td></tr><tr><td><code>CUSTOM</code> </td><td>no
</td></tr><tr><td><code>DATE</code> </td><td>no <
/td></tr><tr><td><code>DECIMAL</code> </td><td>no
</td></tr><tr><td><code>DELETE</code> </td><td>yes
</td></tr><tr><td><code>DESC</code> </td><td>yes
</td></tr><tr><td><code>DESCRIBE</code> </td><td>yes
</td></tr><tr><td><code>DISTINCT</code> </td><td>no
</td></tr><tr><td><code>DOUBLE</code> </td><td>no
</td></tr><tr><td><code>DROP</code> </td><td>yes
</td></tr><tr><td><code>ENTRIES</code> </td><td>yes
</td></tr><tr><td><code>EXECUTE</code> </td><td>yes
</td></tr><tr><td><code>EXISTS</code> </td><td>no
</td></tr><tr><td><code>FILTERING</code> </td><td>no
</td></tr><tr><td><code>FINALFUNC</code> </td><td>no
</td></tr><tr><td><code>FLOAT</code> </td><td>no
</td></tr><tr><td><code>FROM</code> </td><td>yes
</td></tr><tr><td><code>FROZEN</code> </td><td>no
</td></tr><tr><td><code>FULL</code> </td><td>yes
</td></tr><tr><td><code>FUNCTION</code> </td><td>no
</td></tr><tr><td><code>FUNCT
IONS</code> </td><td>no </td></tr><tr><td><code>GRANT</code>
</td><td>yes </td></tr><tr><td><code>IF</code> </td><td>yes
</td></tr><tr><td><code>IN</code> </td><td>yes
</td></tr><tr><td><code>INDEX</code> </td><td>yes
</td></tr><tr><td><code>INET</code> </td><td>no
</td></tr><tr><td><code>INFINITY</code> </td><td>yes
</td></tr><tr><td><code>INITCOND</code> </td><td>no
</td></tr><tr><td><code>INPUT</code> </td><td>no
</td></tr><tr><td><code>INSERT</code> </td><td>yes
</td></tr><tr><td><code>INT</code> </td><td>no
</td></tr><tr><td><code>INTO</code> </td><td>yes
</td></tr><tr><td><code>JSON</code> </td><td>no
</td></tr><tr><td><code>KEY</code> </td><td>no
</td></tr><tr><td><code>KEYS</code> </td><td>no
</td></tr><tr><td><code>KEYSPACE</code> </td><td>yes
</td></tr><tr><td><code>KEYSPACES</code> </td><td>no
</td></tr><tr><td><code>LANGUAGE</code> </td><td>no
</td></tr><tr><td><code>LIMIT</code> </td><td>yes
</td></tr><tr><td><code>LIST</code> </td><td>no
</td></tr><tr><td><code>LOGIN</code> </td><td>no
</td></tr><tr><td><code>MAP</code> </td><td>no
</td></tr><tr><td><code>MODIFY</code> </td><td>yes
</td></tr><tr><td><code>NAN</code> </td><td>yes
</td></tr><tr><td><code>NOLOGIN</code> </td><td>no
</td></tr><tr><td><code>NORECURSIVE</code> </td><td>yes
</td></tr><tr><td><code>NOSUPERUSER</code> </td><td>no
</td></tr><tr><td><code>NOT</code> </td><td>yes
</td></tr><tr><td><code>NULL</code> </td><td>yes
</td></tr><tr><td><code>OF</code> </td><td>yes
</td></tr><tr><td><code>ON</code> </td><td>yes
</td></tr><tr><td><code>OPTIONS</code> </td><td>no
</td></tr><tr><td><code>OR</code> </td><td>yes
</td></tr><tr><td><code>ORDER</code> </td><td>yes
</td></tr><tr><td><code>PASSWORD</code> </td><td>no
</td></tr><tr><td><code>PERM
ISSION</code> </td><td>no </td></tr><tr><td><code>PERMISSIONS</code>
</td><td>no </td></tr><tr><td><code>PRIMARY</code> </td><td>yes
</td></tr><tr><td><code>RENAME</code> </td><td>yes
</td></tr><tr><td><code>REPLACE</code> </td><td>yes
</td></tr><tr><td><code>RETURNS</code> </td><td>no
</td></tr><tr><td><code>REVOKE</code> </td><td>yes
</td></tr><tr><td><code>ROLE</code> </td><td>no
</td></tr><tr><td><code>ROLES</code> </td><td>no
</td></tr><tr><td><code>SCHEMA</code> </td><td>yes
</td></tr><tr><td><code>SELECT</code> </td><td>yes
</td></tr><tr><td><code>SET</code> </td><td>yes
</td></tr><tr><td><code>SFUNC</code> </td><td>no
</td></tr><tr><td><code>SMALLINT</code> </td><td>no
</td></tr><tr><td><code>STATIC</code> </td><td>no
</td></tr><tr><td><code>STORAGE</code> </td><td>no
</td></tr><tr><td><code>STYPE</code> </td><td>no
</td></tr><tr><td><code>SUPERUSER</code> </td><td>no
</td></tr><tr><td><code>TABLE</code> </td><td>yes
</td></tr><tr><td><code>TEXT</code> </td><td>no
</td></tr><tr><td><code>TIME</code> </td><td>no
</td></tr><tr><td><code>TIMESTAMP</code> </td><td>no
</td></tr><tr><td><code>TIMEUUID</code> </td><td>no
</td></tr><tr><td><code>TINYINT</code> </td><td>no
</td></tr><tr><td><code>TO</code> </td><td>yes
</td></tr><tr><td><code>TOKEN</code> </td><td>yes
</td></tr><tr><td><code>TRIGGER</code> </td><td>no
</td></tr><tr><td><code>TRUNCATE</code> </td><td>yes
</td></tr><tr><td><code>TTL</code> </td><td>no
</td></tr><tr><td><code>TUPLE</code> </td><td>no
</td></tr><tr><td><code>TYPE</code> </td><td>no
</td></tr><tr><td><code>UNLOGGED</code> </td><td>yes
</td></tr><tr><td><code>UPDATE</code> </td><td>yes
</td></tr><tr><td><code>USE</code> </td><td>yes
</td></tr><tr><td><code>USER</code> </td><td>no
</td></tr><tr><td><code>USE
RS</code> </td><td>no </td></tr><tr><td><code>USING</code>
</td><td>yes </td></tr><tr><td><code>UUID</code> </td><td>no
</td></tr><tr><td><code>VALUES</code> </td><td>no
</td></tr><tr><td><code>VARCHAR</code> </td><td>no
</td></tr><tr><td><code>VARINT</code> </td><td>no
</td></tr><tr><td><code>WHERE</code> </td><td>yes
</td></tr><tr><td><code>WITH</code> </td><td>yes
</td></tr><tr><td><code>WRITETIME</code> </td><td>no </td></tr></table><h2
id="appendixB">Appendix B: CQL Reserved Types</h2><p>The following type names
are not currently used by CQL, but are reserved for potential future use.
User-defined types may not use reserved type names as their
name.</p><table><tr><th>type </th></tr><tr><td><code>bitstring</code>
</td></tr><tr><td><code>byte</code> </td></tr><tr><td><code>complex</code>
</td></tr><tr><td><code>date</code> </td></tr><tr><td><code>enum</code>
</td></tr><tr><td><code>interval</cod
e> </td></tr><tr><td><code>macaddr</code>
</td></tr><tr><td><code>smallint</code> </td></tr></table><h2
id="changes">Changes</h2><p>The following describes the changes in each version
of CQL.</p><h3 id="a3.3.1">3.3.1</h3><ul><li>The syntax <code>TRUNCATE TABLE
X</code> is now accepted as an alias for <code>TRUNCATE X</code></li></ul><h3
id="a3.3.0">3.3.0</h3><ul><li>Adds new <a
href="#aggregates">aggregates</a></li><li>User-defined functions are now
supported through <a href="#createFunctionStmt"><code>CREATE
FUNCTION</code></a> and <a href="#dropFunctionStmt"><code>DROP
FUNCTION</code></a>.</li><li>User-defined aggregates are now supported through
<a href="#createAggregateStmt"><code>CREATE AGGREGATE</code></a> and <a
href="#dropAggregateStmt"><code>DROP AGGREGATE</code></a>.</li><li>Allows
double-dollar enclosed strings literals as an alternative to single-quote
enclosed strings.</li><li>Introduces Roles to supercede user based
authentication and access control</li><li><a href
="#usingdates"><code>Date</code></a> and <a
href="usingtime"><code>Time</code></a> data types have been added</li><li><a
href="#json"><code>JSON</code></a> support has been
added</li><li><code>Tinyint</code> and <code>Smallint</code> data types have
been added</li><li>Adds new time conversion functions and deprecate
<code>dateOf</code> and <code>unixTimestampOf</code>. See <a
href="#timeFun"><code>Time conversion functions</code></a></li></ul><h3
id="a3.2.0">3.2.0</h3><ul><li>User-defined types are now supported through <a
href="#createTypeStmt"><code>CREATE TYPE</code></a>, <a
href="#alterTypeStmt"><code>ALTER TYPE</code></a>, and <a
href="#dropTypeStmt"><code>DROP TYPE</code></a></li><li><a
href="#createIndexStmt"><code>CREATE INDEX</code></a> now supports indexing
collection columns, including indexing the keys of map collections through the
<code>keys()</code> function</li><li>Indexes on collections may be queried
using the new <code>CONTAINS</code> and <code>CONTAINS KEY</code>
operators</li><li>Tuple types were added to hold fixed-length sets of typed
positional fields (see the section on <a href="#types">types</a> )</li><li><a
href="#dropIndexStmt"><code>DROP INDEX</code></a> now supports optionally
specifying a keyspace</li></ul><h3
id="a3.1.7">3.1.7</h3><ul><li><code>SELECT</code> statements now support
selecting multiple rows in a single partition using an <code>IN</code> clause
on combinations of clustering columns. See <a href="#selectWhere">SELECT
WHERE</a> clauses.</li><li><code>IF NOT EXISTS</code> and <code>IF
EXISTS</code> syntax is now supported by <code>CREATE USER</code> and
<code>DROP USER</code> statmenets, respectively.</li></ul><h3
id="a3.1.6">3.1.6</h3><ul><li>A new <a href="#uuidFun"><code>uuid</code>
method</a> has been added.</li><li>Support for <code>DELETE ... IF
EXISTS</code> syntax.</li></ul><h3 id="a3.1.5">3.1.5</h3><ul><li>It is now
possible to group clustering columns in a relatiion, see <a
href="#selectWhere">SELECT WHERE</
a> clauses.</li><li>Added support for <code>STATIC</code> columns, see <a
href="#createTableStatic">static in CREATE TABLE</a>.</li></ul><h3
id="a3.1.4">3.1.4</h3><ul><li><code>CREATE INDEX</code> now allows specifying
options when creating CUSTOM indexes (see <a href="#createIndexStmt">CREATE
INDEX reference</a> ).</li></ul><h3 id="a3.1.3">3.1.3</h3><ul><li>Millisecond
precision formats have been added to the timestamp parser (see <a
href="#usingtimestamps">working with dates</a> ).</li></ul><h3
id="a3.1.2">3.1.2</h3><ul><li><code>NaN</code> and <code>Infinity</code> has
been added as valid float contants. They are now reserved keywords. In the
unlikely case you we using them as a column identifier (or keyspace/table one),
you will noew need to double quote them (see <a href="#identifiers">quote
identifiers</a> ).</li></ul><h3
id="a3.1.1">3.1.1</h3><ul><li><code>SELECT</code> statement now allows listing
the partition keys (using the <code>DISTINCT</code> modifier). See <a href="ht
tps://issues.apache.org/jira/browse/CASSANDRA-4536">CASSANDRA-4536</a>.</li><li>The
syntax <code>c IN ?</code> is now supported in <code>WHERE</code> clauses. In
that case, the value expected for the bind variable will be a list of whatever
type <code>c</code> is.</li><li>It is now possible to use named bind variables
(using <code>:name</code> instead of <code>?</code>).</li></ul><h3
id="a3.1.0">3.1.0</h3><ul><li><a href="#alterTableStmt">ALTER TABLE</a>
<code>DROP</code> option has been reenabled for CQL3 tables and has new
semantics now: the space formerly used by dropped columns will now be
eventually reclaimed (post-compaction). You should not readd previously dropped
columns unless you use timestamps with microsecond precision (see <a
href="https://issues.apache.org/jira/browse/CASSANDRA-3919";>CASSANDRA-3919</a>
for more details).</li><li><code>SELECT</code> statement now supports aliases
in select clause. Aliases in WHERE and ORDER BY clauses are not supported. See
the <a href
="#selectStmt">section on select</a> for details.</li><li><code>CREATE</code>
statements for <code>KEYSPACE</code>, <code>TABLE</code> and <code>INDEX</code>
now supports an <code>IF NOT EXISTS</code> condition. Similarly,
<code>DROP</code> statements support a <code>IF EXISTS</code>
condition.</li><li><code>INSERT</code> statements optionally supports a
<code>IF NOT EXISTS</code> condition and <code>UPDATE</code> supports
<code>IF</code> conditions.</li></ul><h3
id="a3.0.5">3.0.5</h3><ul><li><code>SELECT</code>, <code>UPDATE</code>, and
<code>DELETE</code> statements now allow empty <code>IN</code> relations (see
<a
href="https://issues.apache.org/jira/browse/CASSANDRA-5626";>CASSANDRA-5626</a>).</li></ul><h3
id="a3.0.4">3.0.4</h3><ul><li>Updated the syntax for custom <a
href="#createIndexStmt">secondary indexes</a>.</li><li>Non-equal condition on
the partition key are now never supported, even for ordering partitioner as
this was not correct (the order was <strong>not</strong> the
one of the type of the partition key). Instead, the <code>token</code> method
should always be used for range queries on the partition key (see <a
href="#selectWhere">WHERE clauses</a> ).</li></ul><h3
id="a3.0.3">3.0.3</h3><ul><li>Support for custom <a
href="#createIndexStmt">secondary indexes</a> has been added.</li></ul><h3
id="a3.0.2">3.0.2</h3><ul><li>Type validation for the <a
href="#constants">constants</a> has been fixed. For instance, the
implementation used to allow <code>'2'</code> as a valid value for an
<code>int</code> column (interpreting it has the equivalent of <code>2</code>),
or <code>42</code> as a valid <code>blob</code> value (in which case
<code>42</code> was interpreted as an hexadecimal representation of the blob).
This is no longer the case, type validation of constants is now more strict.
See the <a href="#types">data types</a> section for details on which constant
is allowed for which type.</li><li>The type validation fixed of the previous
point has lead t
o the introduction of <a href="#constants">blobs constants</a> to allow
inputing blobs. Do note that while inputing blobs as strings constant is still
supported by this version (to allow smoother transition to blob constant), it
is now deprecated (in particular the <a href="#types">data types</a> section
does not list strings constants as valid blobs) and will be removed by a future
version. If you were using strings as blobs, you should thus update your client
code ASAP to switch blob constants.</li><li>A number of functions to convert
native types to blobs have also been introduced. Furthermore the token function
is now also allowed in select clauses. See the <a href="#functions">section on
functions</a> for details.</li></ul><h3 id="a3.0.1">3.0.1</h3><ul><li><a
href="#usingtimestamps">Date strings</a> (and timestamps) are no longer
accepted as valid <code>timeuuid</code> values. Doing so was a bug in the sense
that date string are not valid <code>timeuuid</code>, and it was thus
resulting in <a
href="https://issues.apache.org/jira/browse/CASSANDRA-4936";>confusing
behaviors</a>. However, the following new methods have been added to help
working with <code>timeuuid</code>: <code>now</code>, <code>minTimeuuid</code>,
<code>maxTimeuuid</code> , <code>dateOf</code> and
<code>unixTimestampOf</code>. See the <a href="#timeuuidFun">section dedicated
to these methods</a> for more detail.</li><li>“Float
constants”#constants now support the exponent notation. In other words,
<code>4.2E10</code> is now a valid floating point value.</li></ul><h2
id="Versioning">Versioning</h2><p>Versioning of the CQL language adheres to the
<a href="http://semver.org";>Semantic Versioning</a> guidelines. Versions take
the form X.Y.Z where X, Y, and Z are integer values representing major, minor,
and patch level respectively. There is no correlation between Cassandra release
versions and the CQL language
version.</p><table><tr><th>version</th><th>description</th></tr><tr><td>
Major </td><td>The major version <em>must</em> be bumped when backward
incompatible changes are introduced. This should rarely
occur.</td></tr><tr><td>Minor </td><td>Minor version increments occur when
new, but backward compatible, functionality is
introduced.</td></tr><tr><td>Patch </td><td>The patch version is
incremented when bugs are fixed.</td></tr></table></body></html>
\ No newline at end of file
+</pre></pre><p>Any columns which are ommitted from the <code>JSON</code> map
will be defaulted to a <code>NULL</code> value (which will result in a
tombstone being created).</p><h3 id="jsonEncoding">JSON Encoding of Cassandra
Data Types</h3><p>Where possible, Cassandra will represent and accept data
types in their native <code>JSON</code> representation. Cassandra will also
accept string representations matching the CQL literal format for all
single-field types. For example, floats, ints, UUIDs, and dates can be
represented by CQL literal strings. However, compound types, such as
collections, tuples, and user-defined types must be represented by native
<code>JSON</code> collections (maps and lists) or a JSON-encoded string
representation of the collection.</p><p>The following table describes the
encodings that Cassandra will accept in <code>INSERT JSON</code> values (and
<code>fromJson()</code> arguments) as well as the format Cassandra will use
when returning data for <code>SELE
CT JSON</code> statements (and
<code>fromJson()</code>):</p><table><tr><th>type </th><th>formats accepted
</th><th>return format </th><th>notes</th></tr><tr><td><code>ascii</code>
</td><td>string </td><td>string </td><td>Uses
JSON’s <code>\u</code> character
escape</td></tr><tr><td><code>bigint</code> </td><td>integer, string
</td><td>integer </td><td>String must be valid 64 bit
integer</td></tr><tr><td><code>blob</code> </td><td>string
</td><td>string </td><td>String should be 0x followed by an even
number of hex digits</td></tr><tr><td><code>boolean</code> </td><td>boolean,
string </td><td>boolean </td><td>String must be
“true” or "false"</td></tr><tr><td><code>date</code>
</td><td>string </td><td>string </td><td>Date in
format <code>YYYY-MM-DD</code>, timezone
UTC</td></tr><tr><td><code>decimal</code> </td><td>integer, float,
string</td><t
d>float </td><td>May exceed 32 or 64-bit IEEE-754 floating point
precision in client-side decoder</td></tr><tr><td><code>double</code>
</td><td>integer, float, string</td><td>float </td><td>String must
be valid integer or float</td></tr><tr><td><code>float</code>
</td><td>integer, float, string</td><td>float </td><td>String must
be valid integer or float</td></tr><tr><td><code>inet</code>
</td><td>string </td><td>string </td><td>IPv4 or IPv6
address</td></tr><tr><td><code>int</code> </td><td>integer, string
</td><td>integer </td><td>String must be valid 32 bit
integer</td></tr><tr><td><code>list</code> </td><td>list, string
</td><td>list </td><td>Uses JSON’s native list
representation</td></tr><tr><td><code>map</code> </td><td>map, string
</td><td>map </td><td>Uses JSON’s native map
representation</td></tr><tr><td><code>smallint</cod
e> </td><td>integer, string </td><td>integer </td><td>String
must be valid 16 bit integer</td></tr><tr><td><code>set</code>
</td><td>list, string </td><td>list </td><td>Uses
JSON’s native list representation</td></tr><tr><td><code>text</code>
</td><td>string </td><td>string </td><td>Uses
JSON’s <code>\u</code> character
escape</td></tr><tr><td><code>time</code> </td><td>string
</td><td>string </td><td>Time of day in format
<code>HH-MM-SS[.fffffffff]</code></td></tr><tr><td><code>timestamp</code></td><td>integer,
string </td><td>string </td><td>A timestamp. Strings constant
are allow to input timestamps as dates, see <a href="#usingdates">Working with
dates</a> below for more information. Datestamps with format <code>YYYY-MM-DD
HH:MM:SS.SSS</code> are returned.</td></tr><tr><td><code>timeuuid</code>
</td><td>string </td><td>string </
td><td>Type 1 UUID. See <a href="#constants">Constants</a> for the UUID
format</td></tr><tr><td><code>tinyint</code> </td><td>integer, string
</td><td>integer </td><td>String must be valid 8 bit
integer</td></tr><tr><td><code>tuple</code> </td><td>list, string
</td><td>list </td><td>Uses JSON’s native list
representation</td></tr><tr><td><code>UDT</code> </td><td>map, string
</td><td>map </td><td>Uses JSON’s native map
representation with field names as keys</td></tr><tr><td><code>uuid</code>
</td><td>string </td><td>string </td><td>See <a
href="#constants">Constants</a> for the UUID
format</td></tr><tr><td><code>varchar</code> </td><td>string
</td><td>string </td><td>Uses JSON’s <code>\u</code> character
escape</td></tr><tr><td><code>varint</code> </td><td>integer, string
</td><td>integer </td><td>Variable length; may overflow
32 or 64 bit integers in client-side decoder</td></tr></table><h3
id="fromJson">The fromJson() Function</h3><p>The <code>fromJson()</code>
function may be used similarly to <code>INSERT JSON</code>, but for a single
column value. It may only be used in the <code>VALUES</code> clause of an
<code>INSERT</code> statement or as one of the column values in an
<code>UPDATE</code>, <code>DELETE</code>, or <code>SELECT</code> statement.
For example, it cannot be used in the selection clause of a <code>SELECT</code>
statement.</p><h3 id="toJson">The toJson() Function</h3><p>The
<code>toJson()</code> function may be used similarly to <code>SELECT
JSON</code>, but for a single column value. It may only be used in the
selection clause of a <code>SELECT</code> statement.</p><h2
id="appendixA">Appendix A: CQL Keywords</h2><p>CQL distinguishes between
<em>reserved</em> and <em>non-reserved</em> keywords. Reserved keywords cannot
be used as identifier, they are truly reserved for the language (
but one can enclose a reserved keyword by double-quotes to use it as an
identifier). Non-reserved keywords however only have a specific meaning in
certain context but can used as identifer otherwise. The only <em>raison
d'être</em> of these non-reserved keywords is convenience: some keyword are
non-reserved when it was always easy for the parser to decide whether they were
used as keywords or not.</p><table><tr><th>Keyword </th><th>Reserved?
</th></tr><tr><td><code>ADD</code> </td><td>yes
</td></tr><tr><td><code>AGGREGATE</code> </td><td>no
</td></tr><tr><td><code>ALL</code> </td><td>no
</td></tr><tr><td><code>ALLOW</code> </td><td>yes
</td></tr><tr><td><code>ALTER</code> </td><td>yes
</td></tr><tr><td><code>AND</code> </td><td>yes
</td></tr><tr><td><code>APPLY</code> </td><td>yes
</td></tr><tr><td><code>AS</code> </td><td>no
</td></tr><tr><td><code>ASC</code> </td><td>yes
</td></tr><tr><td><code>ASCII<
/code> </td><td>no </td></tr><tr><td><code>AUTHORIZE</code>
</td><td>yes </td></tr><tr><td><code>BATCH</code> </td><td>yes
</td></tr><tr><td><code>BEGIN</code> </td><td>yes
</td></tr><tr><td><code>BIGINT</code> </td><td>no
</td></tr><tr><td><code>BLOB</code> </td><td>no
</td></tr><tr><td><code>BOOLEAN</code> </td><td>no
</td></tr><tr><td><code>BY</code> </td><td>yes
</td></tr><tr><td><code>CALLED</code> </td><td>no
</td></tr><tr><td><code>CLUSTERING</code> </td><td>no
</td></tr><tr><td><code>COLUMNFAMILY</code> </td><td>yes
</td></tr><tr><td><code>COMPACT</code> </td><td>no
</td></tr><tr><td><code>CONTAINS</code> </td><td>no
</td></tr><tr><td><code>COUNT</code> </td><td>no
</td></tr><tr><td><code>COUNTER</code> </td><td>no
</td></tr><tr><td><code>CREATE</code> </td><td>yes
</td></tr><tr><td><code>CUSTOM</code> </td><td>no
</td></tr><tr><td><code>DATE</code> </td><td>no <
/td></tr><tr><td><code>DECIMAL</code> </td><td>no
</td></tr><tr><td><code>DELETE</code> </td><td>yes
</td></tr><tr><td><code>DESC</code> </td><td>yes
</td></tr><tr><td><code>DESCRIBE</code> </td><td>yes
</td></tr><tr><td><code>DISTINCT</code> </td><td>no
</td></tr><tr><td><code>DOUBLE</code> </td><td>no
</td></tr><tr><td><code>DROP</code> </td><td>yes
</td></tr><tr><td><code>ENTRIES</code> </td><td>yes
</td></tr><tr><td><code>EXECUTE</code> </td><td>yes
</td></tr><tr><td><code>EXISTS</code> </td><td>no
</td></tr><tr><td><code>FILTERING</code> </td><td>no
</td></tr><tr><td><code>FINALFUNC</code> </td><td>no
</td></tr><tr><td><code>FLOAT</code> </td><td>no
</td></tr><tr><td><code>FROM</code> </td><td>yes
</td></tr><tr><td><code>FROZEN</code> </td><td>no
</td></tr><tr><td><code>FULL</code> </td><td>yes
</td></tr><tr><td><code>FUNCTION</code> </td><td>no
</td></tr><tr><td><code>FUNCT
IONS</code> </td><td>no </td></tr><tr><td><code>GRANT</code>
</td><td>yes </td></tr><tr><td><code>IF</code> </td><td>yes
</td></tr><tr><td><code>IN</code> </td><td>yes
</td></tr><tr><td><code>INDEX</code> </td><td>yes
</td></tr><tr><td><code>INET</code> </td><td>no
</td></tr><tr><td><code>INFINITY</code> </td><td>yes
</td></tr><tr><td><code>INITCOND</code> </td><td>no
</td></tr><tr><td><code>INPUT</code> </td><td>no
</td></tr><tr><td><code>INSERT</code> </td><td>yes
</td></tr><tr><td><code>INT</code> </td><td>no
</td></tr><tr><td><code>INTO</code> </td><td>yes
</td></tr><tr><td><code>JSON</code> </td><td>no
</td></tr><tr><td><code>KEY</code> </td><td>no
</td></tr><tr><td><code>KEYS</code> </td><td>no
</td></tr><tr><td><code>KEYSPACE</code> </td><td>yes
</td></tr><tr><td><code>KEYSPACES</code> </td><td>no
</td></tr><tr><td><code>LANGUAGE</code> </td><td>no
</td></tr><tr><td><code>LIMIT</code> </td><td>yes
</td></tr><tr><td><code>LIST</code> </td><td>no
</td></tr><tr><td><code>LOGIN</code> </td><td>no
</td></tr><tr><td><code>MAP</code> </td><td>no
</td></tr><tr><td><code>MODIFY</code> </td><td>yes
</td></tr><tr><td><code>NAN</code> </td><td>yes
</td></tr><tr><td><code>NOLOGIN</code> </td><td>no
</td></tr><tr><td><code>NORECURSIVE</code> </td><td>yes
</td></tr><tr><td><code>NOSUPERUSER</code> </td><td>no
</td></tr><tr><td><code>NOT</code> </td><td>yes
</td></tr><tr><td><code>NULL</code> </td><td>yes
</td></tr><tr><td><code>OF</code> </td><td>yes
</td></tr><tr><td><code>ON</code> </td><td>yes
</td></tr><tr><td><code>OPTIONS</code> </td><td>no
</td></tr><tr><td><code>OR</code> </td><td>yes
</td></tr><tr><td><code>ORDER</code> </td><td>yes
</td></tr><tr><td><code>PASSWORD</code> </td><td>no
</td></tr><tr><td><code>PERM
ISSION</code> </td><td>no </td></tr><tr><td><code>PERMISSIONS</code>
</td><td>no </td></tr><tr><td><code>PRIMARY</code> </td><td>yes
</td></tr><tr><td><code>RENAME</code> </td><td>yes
</td></tr><tr><td><code>REPLACE</code> </td><td>yes
</td></tr><tr><td><code>RETURNS</code> </td><td>no
</td></tr><tr><td><code>REVOKE</code> </td><td>yes
</td></tr><tr><td><code>ROLE</code> </td><td>no
</td></tr><tr><td><code>ROLES</code> </td><td>no
</td></tr><tr><td><code>SCHEMA</code> </td><td>yes
</td></tr><tr><td><code>SELECT</code> </td><td>yes
</td></tr><tr><td><code>SET</code> </td><td>yes
</td></tr><tr><td><code>SFUNC</code> </td><td>no
</td></tr><tr><td><code>SMALLINT</code> </td><td>no
</td></tr><tr><td><code>STATIC</code> </td><td>no
</td></tr><tr><td><code>STORAGE</code> </td><td>no
</td></tr><tr><td><code>STYPE</code> </td><td>no
</td></tr><tr><td><code>SUPERUSER</code> </td><td>no
</td></tr><tr><td><code>TABLE</code> </td><td>yes
</td></tr><tr><td><code>TEXT</code> </td><td>no
</td></tr><tr><td><code>TIME</code> </td><td>no
</td></tr><tr><td><code>TIMESTAMP</code> </td><td>no
</td></tr><tr><td><code>TIMEUUID</code> </td><td>no
</td></tr><tr><td><code>TINYINT</code> </td><td>no
</td></tr><tr><td><code>TO</code> </td><td>yes
</td></tr><tr><td><code>TOKEN</code> </td><td>yes
</td></tr><tr><td><code>TRIGGER</code> </td><td>no
</td></tr><tr><td><code>TRUNCATE</code> </td><td>yes
</td></tr><tr><td><code>TTL</code> </td><td>no
</td></tr><tr><td><code>TUPLE</code> </td><td>no
</td></tr><tr><td><code>TYPE</code> </td><td>no
</td></tr><tr><td><code>UNLOGGED</code> </td><td>yes
</td></tr><tr><td><code>UPDATE</code> </td><td>yes
</td></tr><tr><td><code>USE</code> </td><td>yes
</td></tr><tr><td><code>USER</code> </td><td>no
</td></tr><tr><td><code>USE
RS</code> </td><td>no </td></tr><tr><td><code>USING</code>
</td><td>yes </td></tr><tr><td><code>UUID</code> </td><td>no
</td></tr><tr><td><code>VALUES</code> </td><td>no
</td></tr><tr><td><code>VARCHAR</code> </td><td>no
</td></tr><tr><td><code>VARINT</code> </td><td>no
</td></tr><tr><td><code>WHERE</code> </td><td>yes
</td></tr><tr><td><code>WITH</code> </td><td>yes
</td></tr><tr><td><code>WRITETIME</code> </td><td>no </td></tr></table><h2
id="appendixB">Appendix B: CQL Reserved Types</h2><p>The following type names
are not currently used by CQL, but are reserved for potential future use.
User-defined types may not use reserved type names as their
name.</p><table><tr><th>type </th></tr><tr><td><code>bitstring</code>
</td></tr><tr><td><code>byte</code> </td></tr><tr><td><code>complex</code>
</td></tr><tr><td><code>date</code> </td></tr><tr><td><code>enum</code>
</td></tr><tr><td><code>interval</cod
e> </td></tr><tr><td><code>macaddr</code>
</td></tr><tr><td><code>smallint</code> </td></tr></table><h2
id="changes">Changes</h2><p>The following describes the changes in each version
of CQL.</p><h3 id="a3.4.0">3.4.0</h3><ul><li>Support for <a
href="#createMVStmt">materialized views</a></li></ul><h3
id="a3.3.1">3.3.1</h3><ul><li>The syntax <code>TRUNCATE TABLE X</code> is now
accepted as an alias for <code>TRUNCATE X</code></li></ul><h3
id="a3.3.0">3.3.0</h3><ul><li>Adds new <a
href="#aggregates">aggregates</a></li><li>User-defined functions are now
supported through <a href="#createFunctionStmt"><code>CREATE
FUNCTION</code></a> and <a href="#dropFunctionStmt"><code>DROP
FUNCTION</code></a>.</li><li>User-defined aggregates are now supported through
<a href="#createAggregateStmt"><code>CREATE AGGREGATE</code></a> and <a
href="#dropAggregateStmt"><code>DROP AGGREGATE</code></a>.</li><li>Allows
double-dollar enclosed strings literals as an alternative to single-quote
enclosed strin
gs.</li><li>Introduces Roles to supercede user based authentication and access
control</li><li><a href="#usingdates"><code>Date</code></a> and <a
href="usingtime"><code>Time</code></a> data types have been added</li><li><a
href="#json"><code>JSON</code></a> support has been
added</li><li><code>Tinyint</code> and <code>Smallint</code> data types have
been added</li><li>Adds new time conversion functions and deprecate
<code>dateOf</code> and <code>unixTimestampOf</code>. See <a
href="#timeFun"><code>Time conversion functions</code></a></li></ul><h3
id="a3.2.0">3.2.0</h3><ul><li>User-defined types are now supported through <a
href="#createTypeStmt"><code>CREATE TYPE</code></a>, <a
href="#alterTypeStmt"><code>ALTER TYPE</code></a>, and <a
href="#dropTypeStmt"><code>DROP TYPE</code></a></li><li><a
href="#createIndexStmt"><code>CREATE INDEX</code></a> now supports indexing
collection columns, including indexing the keys of map collections through the
<code>keys()</code> function</li><li>I
ndexes on collections may be queried using the new <code>CONTAINS</code> and
<code>CONTAINS KEY</code> operators</li><li>Tuple types were added to hold
fixed-length sets of typed positional fields (see the section on <a
href="#types">types</a> )</li><li><a href="#dropIndexStmt"><code>DROP
INDEX</code></a> now supports optionally specifying a keyspace</li></ul><h3
id="a3.1.7">3.1.7</h3><ul><li><code>SELECT</code> statements now support
selecting multiple rows in a single partition using an <code>IN</code> clause
on combinations of clustering columns. See <a href="#selectWhere">SELECT
WHERE</a> clauses.</li><li><code>IF NOT EXISTS</code> and <code>IF
EXISTS</code> syntax is now supported by <code>CREATE USER</code> and
<code>DROP USER</code> statmenets, respectively.</li></ul><h3
id="a3.1.6">3.1.6</h3><ul><li>A new <a href="#uuidFun"><code>uuid</code>
method</a> has been added.</li><li>Support for <code>DELETE ... IF
EXISTS</code> syntax.</li></ul><h3 id="a3.1.5">3.1.5</h3><ul><li>It
is now possible to group clustering columns in a relatiion, see <a
href="#selectWhere">SELECT WHERE</a> clauses.</li><li>Added support for
<code>STATIC</code> columns, see <a href="#createTableStatic">static in CREATE
TABLE</a>.</li></ul><h3 id="a3.1.4">3.1.4</h3><ul><li><code>CREATE INDEX</code>
now allows specifying options when creating CUSTOM indexes (see <a
href="#createIndexStmt">CREATE INDEX reference</a> ).</li></ul><h3
id="a3.1.3">3.1.3</h3><ul><li>Millisecond precision formats have been added to
the timestamp parser (see <a href="#usingtimestamps">working with dates</a>
).</li></ul><h3 id="a3.1.2">3.1.2</h3><ul><li><code>NaN</code> and
<code>Infinity</code> has been added as valid float contants. They are now
reserved keywords. In the unlikely case you we using them as a column
identifier (or keyspace/table one), you will noew need to double quote them
(see <a href="#identifiers">quote identifiers</a> ).</li></ul><h3
id="a3.1.1">3.1.1</h3><ul><li><code>SELECT</code> state
ment now allows listing the partition keys (using the <code>DISTINCT</code>
modifier). See <a
href="https://issues.apache.org/jira/browse/CASSANDRA-4536";>CASSANDRA-4536</a>.</li><li>The
syntax <code>c IN ?</code> is now supported in <code>WHERE</code> clauses. In
that case, the value expected for the bind variable will be a list of whatever
type <code>c</code> is.</li><li>It is now possible to use named bind variables
(using <code>:name</code> instead of <code>?</code>).</li></ul><h3
id="a3.1.0">3.1.0</h3><ul><li><a href="#alterTableStmt">ALTER TABLE</a>
<code>DROP</code> option has been reenabled for CQL3 tables and has new
semantics now: the space formerly used by dropped columns will now be
eventually reclaimed (post-compaction). You should not readd previously dropped
columns unless you use timestamps with microsecond precision (see <a
href="https://issues.apache.org/jira/browse/CASSANDRA-3919";>CASSANDRA-3919</a>
for more details).</li><li><code>SELECT</code> statement now suppo
rts aliases in select clause. Aliases in WHERE and ORDER BY clauses are not
supported. See the <a href="#selectStmt">section on select</a> for
details.</li><li><code>CREATE</code> statements for <code>KEYSPACE</code>,
<code>TABLE</code> and <code>INDEX</code> now supports an <code>IF NOT
EXISTS</code> condition. Similarly, <code>DROP</code> statements support a
<code>IF EXISTS</code> condition.</li><li><code>INSERT</code> statements
optionally supports a <code>IF NOT EXISTS</code> condition and
<code>UPDATE</code> supports <code>IF</code> conditions.</li></ul><h3
id="a3.0.5">3.0.5</h3><ul><li><code>SELECT</code>, <code>UPDATE</code>, and
<code>DELETE</code> statements now allow empty <code>IN</code> relations (see
<a
href="https://issues.apache.org/jira/browse/CASSANDRA-5626";>CASSANDRA-5626</a>).</li></ul><h3
id="a3.0.4">3.0.4</h3><ul><li>Updated the syntax for custom <a
href="#createIndexStmt">secondary indexes</a>.</li><li>Non-equal condition on
the partition key are now never sup
ported, even for ordering partitioner as this was not correct (the order was
<strong>not</strong> the one of the type of the partition key). Instead, the
<code>token</code> method should always be used for range queries on the
partition key (see <a href="#selectWhere">WHERE clauses</a> ).</li></ul><h3
id="a3.0.3">3.0.3</h3><ul><li>Support for custom <a
href="#createIndexStmt">secondary indexes</a> has been added.</li></ul><h3
id="a3.0.2">3.0.2</h3><ul><li>Type validation for the <a
href="#constants">constants</a> has been fixed. For instance, the
implementation used to allow <code>'2'</code> as a valid value for an
<code>int</code> column (interpreting it has the equivalent of <code>2</code>),
or <code>42</code> as a valid <code>blob</code> value (in which case
<code>42</code> was interpreted as an hexadecimal representation of the blob).
This is no longer the case, type validation of constants is now more strict.
See the <a href="#types">data types</a> section for details on which
constant is allowed for which type.</li><li>The type validation fixed of the
previous point has lead to the introduction of <a href="#constants">blobs
constants</a> to allow inputing blobs. Do note that while inputing blobs as
strings constant is still supported by this version (to allow smoother
transition to blob constant), it is now deprecated (in particular the <a
href="#types">data types</a> section does not list strings constants as valid
blobs) and will be removed by a future version. If you were using strings as
blobs, you should thus update your client code ASAP to switch blob
constants.</li><li>A number of functions to convert native types to blobs have
also been introduced. Furthermore the token function is now also allowed in
select clauses. See the <a href="#functions">section on functions</a> for
details.</li></ul><h3 id="a3.0.1">3.0.1</h3><ul><li><a
href="#usingtimestamps">Date strings</a> (and timestamps) are no longer
accepted as valid <code>timeuuid</code> values.
Doing so was a bug in the sense that date string are not valid
<code>timeuuid</code>, and it was thus resulting in <a
href="https://issues.apache.org/jira/browse/CASSANDRA-4936";>confusing
behaviors</a>. However, the following new methods have been added to help
working with <code>timeuuid</code>: <code>now</code>, <code>minTimeuuid</code>,
<code>maxTimeuuid</code> , <code>dateOf</code> and
<code>unixTimestampOf</code>. See the <a href="#timeuuidFun">section dedicated
to these methods</a> for more detail.</li><li>“Float
constants”#constants now support the exponent notation. In other words,
<code>4.2E10</code> is now a valid floating point value.</li></ul><h2
id="Versioning">Versioning</h2><p>Versioning of the CQL language adheres to the
<a href="http://semver.org";>Semantic Versioning</a> guidelines. Versions take
the form X.Y.Z where X, Y, and Z are integer values representing major, minor,
and patch level respectively. There is no correlation between Cassandra release
versions and the CQL language
version.</p><table><tr><th>version</th><th>description</th></tr><tr><td>Major
</td><td>The major version <em>must</em> be bumped when backward incompatible
changes are introduced. This should rarely occur.</td></tr><tr><td>Minor
</td><td>Minor version increments occur when new, but backward compatible,
functionality is introduced.</td></tr><tr><td>Patch </td><td>The patch
version is incremented when bugs are fixed.</td></tr></table></body></html>
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