huaxingao commented on a change in pull request #28332: URL: https://github.com/apache/spark/pull/28332#discussion_r415165624
########## File path: docs/sql-ref-syntax-qry-select-like.md ########## @@ -0,0 +1,113 @@ +--- +layout: global +title: LIKE Predicate +displayTitle: LIKE Predicate +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +A LIKE predicate is used to search for a specific pattern. + +### Syntax + +{% highlight sql %} +[ NOT ] { LIKE search_pattern [ ESCAPE esc_char ] | RLIKE regex_pattern } +{% endhighlight %} + +### Parameters + +<dl> + <dt><code><em>search_pattern</em></code></dt> + <dd> + Specifies a string pattern to be searched by the <code>LIKE</code> clause. It can contain special pattern-matching characters: + <ul> + <li><code>%</code></li> matches zero or more characters. + <li><code>_</code></li> matches exactly one character. + </ul> + </dd> +</dl> +<dl> + <dt><code><em>esc_char</em></code></dt> + <dd> + Specifies the escape character. + </dd> +</dl> +<dl> + <dt><code><em>regex_pattern</em></code></dt> + <dd> + Specifies a regular expression search pattern to be searched by the <code>RLIKE</code> clause. + </dd> +</dl> + +### Examples + +{% highlight sql %} +CREATE TABLE person (id INT, name STRING, age INT); +INSERT INTO person VALUES + (100, 'John', 30), + (200, 'Mary', NULL), + (300, 'Mike', 80), + (400, 'Dan', 50), + (500, 'Evan_w', 16); + +SELECT * FROM person WHERE name LIKE 'M%'; ++---+----+----+ +| id|name| age| ++---+----+----+ +|300|Mike| 80| +|200|Mary|null| ++---+----+----+ + +SELECT * FROM person WHERE name LIKE 'M_ry'; ++---+----+----+ +| id|name| age| ++---+----+----+ +|200|Mary|null| ++---+----+----+ + +SELECT * FROM person WHERE name NOT LIKE 'M_ry'; ++---+------+---+ +| id| name|age| ++---+------+---+ +|500|Evan_W| 16| +|300| Mike| 80| +|100| John| 30| +|400| Dan| 50| ++---+------+---+ + +SELECT * FROM person WHERE name RLIKE '[MD]'; ++---+----+----+ +| id|name| age| ++---+----+----+ +|300|Mike| 80| +|400| Dan| 50| +|200|Mary|null| ++---+----+----+ + +SELECT * FROM person WHERE name LIKE '%$_%' ESCAPE '$'; ++---+------+---+ +| id| name|age| ++---+------+---+ +|500|Evan_W| 16| ++---+------+---+ +{% endhighlight %} + +### Related Statements + + * [SELECT](sql-ref-syntax-qry-select.html) + * [WHERE Clause](sql-ref-syntax-qry-select-where.html) Review comment: https://docs.oracle.com/cd/B13789_01/server.101/b10759/conditions016.htm https://docs.snowflake.com/en/sql-reference/functions/like.html ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
