REGEXP_COUNT¶

Syntax¶

REGEXP_COUNT( <subject> ,
              <pattern>
                [ , <position>
                  [ , <parameters> ]
                ]
)

Arguments¶

Required:

subject

The string to search for matches.

pattern

Pattern to match.

For guidelines on specifying patterns, see String functions (regular expressions).

Optional:

position

Number of characters from the beginning of the string where the function starts searching for matches.

Default: 1 (the search for a match starts at the first character on the left)

parameters

String of one or more characters that specifies the parameters used for searching for matches. Supported values:

Parameter	Description
c	Case-sensitive matching
i	Case-insensitive matching
m	Multi-line mode
e	Extract submatches
s	Single-line mode POSIX wildcard character . matches \n

Default: c

For more information, see Specifying the parameters for the regular expression.

Returns¶

Returns a value of type NUMBER. Returns NULL if any argument is NULL.

Usage notes¶

See the General usage notes for regular expression functions.

Collation details¶

Arguments with collation specifications currently aren’t supported.

Examples¶

The following example counts occurrences of the word was. You can use the \b metacharacter to indicate a word boundary. In the following example, matching begins at the first character in the string w and ends at the last character in the string s, and so doesn’t match words that contain the string (such as washing):

SELECT REGEXP_COUNT('It was the best of times, it was the worst of times',
                    '\\bwas\\b',
                    1) AS result;

+--------+
| RESULT |
|--------|
|      2 |
+--------+

The following example uses the i parameter for case-insensitive matching of the character e:

SELECT REGEXP_COUNT('Excelence', 'e', 1, 'i') AS e_in_excelence;

+----------------+
| E_IN_EXCELENCE |
|----------------|
|              4 |
+----------------+

The following example illustrates overlapping occurrences. Create a table and insert data:

CREATE OR REPLACE TABLE overlap (id NUMBER, a STRING);
INSERT INTO overlap VALUES (1,',abc,def,ghi,jkl,');
INSERT INTO overlap VALUES (2,',abc,,def,,ghi,,jkl,');

SELECT * FROM overlap;

+----+----------------------+
| ID | A                    |
|----+----------------------|
|  1 | ,abc,def,ghi,jkl,    |
|  2 | ,abc,,def,,ghi,,jkl, |
+----+----------------------+

Run a query that uses REGEXP_COUNT to count the number of times that the following pattern is found in each row: a punctuation mark followed by digits and letters, followed by a punctuation mark.

SELECT id,
       REGEXP_COUNT(a,
                    '[[:punct:]][[:alnum:]]+[[:punct:]]',
                    1,
                    'i') AS result
  FROM overlap;

+----+--------+
| ID | RESULT |
|----+--------|
|  1 |      2 |
|  2 |      4 |
+----+--------+

The remaining examples use the data in the following table:

CREATE OR REPLACE TABLE regexp_count_demo (dt DATE, messages VARCHAR);

INSERT INTO regexp_count_demo (dt, messages) VALUES
  ('10-AUG-2025','ER-6842,LG-230,LG-150,ER-3379,ER-6210'),
  ('11-AUG-2025','LG-272,LG-605,LG-683,ER-5577'),
  ('12-AUG-2025','ER-2207,LG-551,LG-826,ER-6842');

SELECT * FROM regexp_count_demo;

+------------+---------------------------------------+
| DT         | MESSAGES                              |
|------------+---------------------------------------|
| 2025-08-10 | ER-6842,LG-230,LG-150,ER-3379,ER-6210 |
| 2025-08-11 | LG-272,LG-605,LG-683,ER-5577          |
| 2025-08-12 | ER-2207,LG-551,LG-826,ER-6842         |
+------------+---------------------------------------+

The following query returns the total number of messages for each day by searching for the delimiter (,) and adding one to the total:

SELECT dt,
       REGEXP_COUNT(messages, ',') + 1 AS message_count
  FROM regexp_count_demo;

+------------+---------------+
| DT         | MESSAGE_COUNT |
|------------+---------------|
| 2025-08-10 |             5 |
| 2025-08-11 |             4 |
| 2025-08-12 |             4 |
+------------+---------------+

Assume that errors always begin with ER followed by a hyphen and a four-digit number. The following query counts the number of errors for each day:

SELECT dt,
       REGEXP_COUNT(messages, '\\bER-[0-9]{4}') AS number_of_errors
  FROM regexp_count_demo;

+------------+------------------+
| DT         | NUMBER_OF_ERRORS |
|------------+------------------|
| 2025-08-10 |                3 |
| 2025-08-11 |                1 |
| 2025-08-12 |                2 |
+------------+------------------+