SUBSTR[ING]
Purpose
This function returns a substring of the length length from the position position, out of the string string.
Syntax
substring::=
Usage notes
-
If
lengthis not specified, all of the characters to the end of the string are used. -
If
positionis negative, counting begins at the end of the string. -
If
positionis 0 or 1, the result begins from the first character of the string. -
If
positionis before the start or after the end of the string, the result isNULL. -
For additional information, refer to the functions RIGHT, LEFT, and REGEXP_SUBSTR.
-
MID is an alias for this function.
Example
SELECT SUBSTR('abcdef',2,3) S1,
SUBSTRING('abcdef' FROM 4 FOR 2) S2,
SUBSTR('abcdef',-3) S3,
SUBSTR('abcdef',7) S4,
SUBSTR('abcdef',-7) S5
;
Result:
|
S1 |
S2 |
S3 |
S4 |
S5 |
|---|---|---|---|---|
|
bcd |
de |
def |
NULL |
NULL |