substr

`substr`

Library: ib_udf

Changed in: 1.0, 1.5.2

Description: Returns a string's substring from startpos to endpos, inclusively. Positions are 1-based. If endpos is past the end of the string, Firebird's substr returns all the characters from startpos to the end of the string. InterBase's substr returned NULL in this case.

Return type: CHAR(n)

Syntax (unchanged):

substr (str, startpos, endpos)

Declaration:

DECLARE EXTERNAL FUNCTION substr
   CSTRING(255), SMALLINT, SMALLINT
   RETURNS CSTRING(255) FREE_IT
   ENTRY_POINT 'IB_UDF_substr' MODULE_NAME 'ib_udf'

Notes

In Firebird 1.5.1 and below, the default declaration uses CSTRING(80) instead of CSTRING(255).
Depending on how you declare it (see CSTRING note), this function can accept and return strings of up to 32767 characters.

Tip

Although the function arguments are slightly different, consider using the internal SQL function SUBSTRING instead, for better compatibility.