LOCATE function [String]

Returns the position of one string within another.

Syntax

LOCATE( string-expression-1, string-expression-2 [, integer-expression ] )

Parameters

string-expression-1 The string to be searched.
string-expression-2 The string to be searched for. This string is limited to 255 bytes.
integer-expression The character position in the string to begin the search. The first character is position 1. If the starting offset is negative, the locate function returns the last matching string offset rather than the first. A negative offset indicates how much of the end of the string is to be excluded from the search. The number of bytes excluded is calculated as (-1 * offset) -1.

Remarks

If integer-expression is specified, the search starts at that offset into the string.

The first string can be a long string (longer than 255 bytes), but the second is limited to 255 bytes. If a long string is given as the second argument, the function returns a NULL value. If the string is not found, 0 is returned. Searching for a zero-length string will return 1. If any of the arguments are NULL, the result is NULL.

If multibyte characters are used, with the appropriate collation, then the starting position and the return value may be different from the byte positions.

This function supports NCHAR inputs and/or outputs.

Standards and compatibility

Example

The following statement returns the value 8.

SELECT LOCATE(
   'office party this week - rsvp as soon as possible',
   'party',
   2 );

The following statement:

BEGIN
   DECLARE STR LONG VARCHAR;
   DECLARE POS INT;
   SET str = 'c:\test\functions\locate.sql';
   SET pos = LOCATE( str, '\', -1 );
   select str, pos,
      SUBSTR( str, 1, pos -1 ) AS path,
      SUBSTR( str, pos +1 ) AS filename;
END;

returns the following output:

str	pos	path	filename
c:\test\functions\locate.sql	18	c:\test\functions	locate.sql

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