SUBSTR

The SUBSTR function returns a portion of string, beginning at a specified character position, and a specified number of characters long. SUBSTR calculates lengths using characters as defined by the input character set.

To retrieve a portion of string based on bytes, use SUBSTRB.

Return Value

The return value is the same data type as string.

Syntax

SUBSTR (string , position [, substring_length])

Arguments

string

A text expression that is the base string from which the substring is created.

position

The position at which the first character of the returned string begins.

• When position is 0 (zero), then it is treated as 1.

• When position is positive, then the function counts from the beginning of string to find the first character.

• When position is negative, then the function counts backward from the end of string.

substring_length

The number of characters in the returned string. When you do not specify a value for this argument, then the function returns all characters to the end of string. When you specify a value that is less than 1, the function returns NA.

Examples

The following example returns several specified substrings of "abcdefg".

SHOW SUBSTR('abcdefg',3,4) 
cdef

SHOW SUBSTR('abcdefg',-5,4) 
cdef