Categories:: String & binary functions (Matching/Comparison)

CONTAINS¶

Returns true if expr1 contains expr2. Both expressions must be text or binary expressions.

Tip

You can use the search optimization service to improve the performance of queries that call this function. For details, see Search optimization service.

Syntax¶

CONTAINS( <expr1> , <expr2> )

Arguments¶

expr1: The string to search in.
expr2: The string to search for.

Returns¶

Returns a BOOLEAN or NULL:

Returns TRUE if expr2 is found inside expr1.
Returns FALSE if expr2 is not found inside expr1.
Returns NULL if either input expression is NULL.

Usage notes¶

For comparisons that match a string against more than one specified pattern, you can use the following functions:

Collation details¶

The collation specifications of all input arguments must be compatible.

This function does not support the following collation specifications:

pi (punctuation-insensitive).
cs-ai (case-sensitive, accent-insensitive).

Examples¶

These examples use the CONTAINS function.

Determine whether column values contain a string¶

Create a table with a single column that contains string values.

CREATE OR REPLACE TABLE strings_test (s VARCHAR);

INSERT INTO strings_test values
  ('coffee'),
  ('ice tea'),
  ('latte'),
  ('tea'),
  (NULL);

SELECT * from strings_test;

+---------+
| S       |
|---------|
| coffee  |
| ice tea |
| latte   |
| tea     |
| NULL    |
+---------+

Determine whether the values in column s contain the string te:

SELECT * FROM strings_test WHERE CONTAINS(s, 'te');

+---------+
| S       |
|---------|
| ice tea |
| latte   |
| tea     |
+---------+

Use CONTAINS with collation¶

In the following example, CONTAINS returns different results for the same argument values with different collation specifications.

SELECT CONTAINS(COLLATE('ñ', 'en-ci-ai'), 'n'),
       CONTAINS(COLLATE('ñ', 'es-ci-ai'), 'n');

+-----------------------------------------+-----------------------------------------+
| CONTAINS(COLLATE('Ñ', 'EN-CI-AI'), 'N') | CONTAINS(COLLATE('Ñ', 'ES-CI-AI'), 'N') |
|-----------------------------------------+-----------------------------------------|
| True                                    | False                                   |
+-----------------------------------------+-----------------------------------------+