In studying our JSONB operators, I was confused about what they do based
on the docs. I found that "contain within" means "contain the
path/value", i.e. it has to match the path from the top level, not just
anywhere inside the document:
SELECT '{"a":1, "c" : {"b":2}}'::jsonb @> '{"a":1}'::jsonb;
?column?
----------
t
SELECT '{"a":1, "c" : {"b":2}}'::jsonb @> '{"b":2}'::jsonb;
?column?
----------
f
You can also specify only the top part of the path:
SELECT '{"a":1, "c" : {"b":2}}'::jsonb @> '{"c":{}}'::jsonb;
?column?
----------
t
SELECT '{"a":1, "c" : {"b":2}}'::jsonb @> '{"d":{}}'::jsonb;
?column?
----------
f
I also found that "key/element string exist" really means "string exist
as a top-level key", e.g.
SELECT '{"a":1, "c" : {"b":2}}'::jsonb ? 'a';
?column?
----------
t
SELECT '{"a":1, "c" : {"b":2}}'::jsonb ? 'b';
?column?
----------
f
The attached doc patch and SQL comment update improves this.
--
Bruce Momjian <br...@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ As you are, so once was I. As I am, so you will be. +
+ Roman grave inscription +
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
new file mode 100644
index 897ed64..4ddd01c
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
*************** table2-mapping
*** 10331,10362 ****
<row>
<entry><literal>@></literal></entry>
<entry><type>jsonb</type></entry>
! <entry>Does the left JSON value contain within it the right value?</entry>
<entry><literal>'{"a":1, "b":2}'::jsonb @> '{"b":2}'::jsonb</literal></entry>
</row>
<row>
<entry><literal><@</literal></entry>
<entry><type>jsonb</type></entry>
! <entry>Is the left JSON value contained within the right value?</entry>
<entry><literal>'{"b":2}'::jsonb <@ '{"a":1, "b":2}'::jsonb</literal></entry>
</row>
<row>
<entry><literal>?</literal></entry>
<entry><type>text</type></entry>
! <entry>Does the key/element <emphasis>string</emphasis> exist within
! the JSON value?</entry>
<entry><literal>'{"a":1, "b":2}'::jsonb ? 'b'</literal></entry>
</row>
<row>
<entry><literal>?|</literal></entry>
<entry><type>text[]</type></entry>
! <entry>Do any of these key/element <emphasis>strings</emphasis> exist?</entry>
<entry><literal>'{"a":1, "b":2, "c":3}'::jsonb ?| array['b', 'c']</literal></entry>
</row>
<row>
<entry><literal>?&</literal></entry>
<entry><type>text[]</type></entry>
! <entry>Do all of these key/element <emphasis>strings</emphasis> exist?</entry>
<entry><literal>'["a", "b"]'::jsonb ?& array['a', 'b']</literal></entry>
</row>
<row>
--- 10331,10366 ----
<row>
<entry><literal>@></literal></entry>
<entry><type>jsonb</type></entry>
! <entry>Does the left JSON value contain the right JSON
! path/value entries at the top level?</entry>
<entry><literal>'{"a":1, "b":2}'::jsonb @> '{"b":2}'::jsonb</literal></entry>
</row>
<row>
<entry><literal><@</literal></entry>
<entry><type>jsonb</type></entry>
! <entry>Are the left JSON path/value entries contained at the top level within
! the right JSON value?</entry>
<entry><literal>'{"b":2}'::jsonb <@ '{"a":1, "b":2}'::jsonb</literal></entry>
</row>
<row>
<entry><literal>?</literal></entry>
<entry><type>text</type></entry>
! <entry>Does the <emphasis>string</emphasis> exist as a top-level
! key within the JSON value?</entry>
<entry><literal>'{"a":1, "b":2}'::jsonb ? 'b'</literal></entry>
</row>
<row>
<entry><literal>?|</literal></entry>
<entry><type>text[]</type></entry>
! <entry>Do any of these array <emphasis>strings</emphasis>
! exist as top-level keys?</entry>
<entry><literal>'{"a":1, "b":2, "c":3}'::jsonb ?| array['b', 'c']</literal></entry>
</row>
<row>
<entry><literal>?&</literal></entry>
<entry><type>text[]</type></entry>
! <entry>Do all of these array <emphasis>strings</emphasis> exist
! as top-level keys?</entry>
<entry><literal>'["a", "b"]'::jsonb ?& array['a', 'b']</literal></entry>
</row>
<row>
diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
new file mode 100644
index 1e78558..b4b390b
*** a/doc/src/sgml/json.sgml
--- b/doc/src/sgml/json.sgml
*************** SELECT '"foo"'::jsonb ? 'foo';
*** 369,376 ****
</para>
<para>
The default GIN operator class for <type>jsonb</> supports queries with
! the <literal>@></>, <literal>?</>, <literal>?&</>
! and <literal>?|</> operators.
(For details of the semantics that these operators
implement, see <xref linkend="functions-jsonb-op-table">.)
An example of creating an index with this operator class is:
--- 369,377 ----
</para>
<para>
The default GIN operator class for <type>jsonb</> supports queries with
! top-level key-exists operators <literal>?</>, <literal>?&</>
! and <literal>?|</> operators and path/value-exists operator
! <literal>@></>.
(For details of the semantics that these operators
implement, see <xref linkend="functions-jsonb-op-table">.)
An example of creating an index with this operator class is:
diff --git a/src/include/catalog/pg_operator.h b/src/include/catalog/pg_operator.h
new file mode 100644
index 26c9d4e..eec9c60
*** a/src/include/catalog/pg_operator.h
--- b/src/include/catalog/pg_operator.h
*************** DESCR("greater than or equal");
*** 1806,1816 ****
DATA(insert OID = 3246 ( "@>" PGNSP PGUID b f f 3802 3802 16 3250 0 jsonb_contains contsel contjoinsel ));
DESCR("contains");
DATA(insert OID = 3247 ( "?" PGNSP PGUID b f f 3802 25 16 0 0 jsonb_exists contsel contjoinsel ));
! DESCR("exists");
DATA(insert OID = 3248 ( "?|" PGNSP PGUID b f f 3802 1009 16 0 0 jsonb_exists_any contsel contjoinsel ));
! DESCR("exists any");
DATA(insert OID = 3249 ( "?&" PGNSP PGUID b f f 3802 1009 16 0 0 jsonb_exists_all contsel contjoinsel ));
! DESCR("exists all");
DATA(insert OID = 3250 ( "<@" PGNSP PGUID b f f 3802 3802 16 3246 0 jsonb_contained contsel contjoinsel ));
DESCR("is contained by");
DATA(insert OID = 3284 ( "||" PGNSP PGUID b f f 3802 3802 3802 0 0 jsonb_concat - - ));
--- 1806,1816 ----
DATA(insert OID = 3246 ( "@>" PGNSP PGUID b f f 3802 3802 16 3250 0 jsonb_contains contsel contjoinsel ));
DESCR("contains");
DATA(insert OID = 3247 ( "?" PGNSP PGUID b f f 3802 25 16 0 0 jsonb_exists contsel contjoinsel ));
! DESCR("key exists");
DATA(insert OID = 3248 ( "?|" PGNSP PGUID b f f 3802 1009 16 0 0 jsonb_exists_any contsel contjoinsel ));
! DESCR("any key exists");
DATA(insert OID = 3249 ( "?&" PGNSP PGUID b f f 3802 1009 16 0 0 jsonb_exists_all contsel contjoinsel ));
! DESCR("all keys exist");
DATA(insert OID = 3250 ( "<@" PGNSP PGUID b f f 3802 3802 16 3246 0 jsonb_contained contsel contjoinsel ));
DESCR("is contained by");
DATA(insert OID = 3284 ( "||" PGNSP PGUID b f f 3802 3802 3802 0 0 jsonb_concat - - ));
--
Sent via pgsql-docs mailing list (pgsql-docs@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-docs
