LIKE, NOT LIKE

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The LIKE and NOT LIKE operators are useful for matching patterns containing simple wildcards.

The % character appearing in a pattern matches any string and the _ character matches a single character. For example:

CREATE TABLE like_s (b int, t varchar(20));
INSERT INTO like_s VALUES(0, 'red'), (1, 'blue');
SELECT * FROM like_s WHERE t LIKE 'r_d';
+------+------+
| b    | t    |
+------+------+
|    0 | red  |
+------+------+
SELECT * FROM like_s WHERE t NOT LIKE 'r%';
+------+------+
| b    | t    |
+------+------+
|    1 | blue |
+------+------+

You can use the backslash character \ as an escape character with a LIKE operator so that SingleStore Helios interprets the wildcard character as a literal character. For example:

SELECT "foo_" LIKE "foo\_";
+---------------------+
| "foo_" LIKE "foo\_" |
+---------------------+
|                   1 |
+---------------------+

Caution

Implicit Collation

When character_set_server is set to utf8, string literals with characters using 4-byte encoding are implicitly assigned binary collation and processed as a sequence of bytes rather than characters. This implicit conversion to binary collation causes string functions to return unexpected results. To avoid using implicit binary collation, either use explicit type casting or use database columns defined with the utf8mb4 character set.

For more information, refer to Implicit Collation in Special Cases.

Last modified: February 28, 2023

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