INDEX(a,b,p,s) is an
arithmetic function that determines the position of the substring specified in b within the character string a.The parameter p is optional. If p is specified (p>=1), it defines the start position for the search for the substring b. If p is not specified, the search is started at position 1.
The parameter s is optional. If s is specified, it determines the number of searches for the substring b. If s is not specified, the search is carried out for the first occurrence.
Result of the INDEX(a,b,p,s) function | |
a, b character strings and b not less than s times substring of a |
0 |
a character string and b empty character string |
p |
a,b,p or s is NULL value |
NULL value |
p or s is special NULL value |
Error message |
Model table:
The position of the character string ‘ar’ is to be determined in all customer surnames.
SELECT surname, INDEX(surname, 'ar') position_ar FROM customer
NAME |
POSITION_AR |
Porter |
2 |
DATASOFT |
0 |
Porter |
3 |
Peters |
0 |
Brown |
0 |
Porter |
5 |
Howe |
0 |
Randolph |
0 |
Peters |
0 |
Brown |
0 |
Jackson |
0 |
Adams |
0 |
Griffith |
0 |
TOOLware |
0 |
Brown |
0 |