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Updated on 2023-10-25 GMT+08:00
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regexp_instr

This function is used to return the start or end position of the substring that matches a specified pattern for the occurrence time, starting from start_position in the string source.

Syntax

regexp_instr(string <source>, string <pattern>[,bigint <start_position>[, bigint <occurrence>[, bigint <return_option>]]])

Parameters

Table 1 Parameters

Parameter

Mandatory

Type

Description

source

Yes

STRING

Source string

pattern

Yes

STRING

Constant or regular expression of the STRING type. Pattern to be matched. If the value of this parameter is an empty string, an error is reported.

start_position

No

BIGINT

Constant of the BIGINT type. Start position of the search. If it is not specified, the default value 1 is used.

occurrence

No

BIGINT

Constant of the BIGINT type. It indicates the specified number of matching times. If this parameter is not specified, the default value 1 is used, indicating that the first occurrence position is searched.

return_option

No

BIGINT

Constant of the BIGINT type. This parameter indicates the location to be returned. The value can be 0 or 1. If this parameter is not specified, the default value 0 is used. If this parameter is set to a value of another type or a value that is not allowed, an error message is returned. The value 0 indicates that the start position of the match is returned, and the value 1 indicates that the end position of the match is returned.

Return Values

The return value is of the BIGINT type. return_option indicates the start or end position of the matched substring in source.

  • If the value of pattern is an empty string, an error is reported.
  • If the value of start_position or occurrence is not of the BIGINT type or is less than or equal to 0, an error is reported.
  • If the value of source, pattern, start_position, occurrence, or return_option is NULL, NULL is returned.

Example Code

The value 6 is returned.

select regexp_instr('a1b2c3d4', '[0-9]', 3, 2);

The value NULL is returned.

select regexp_instr('a1b2c3d4', null, 3, 2);
Parent topic: String Functions