Oracle InStr functions

Syntax: InStr (Fatherstr, Sonstr [, Start_position [, Matchtimes]])
Fatherstr: The parent string where to find the substring in this string.
SONSTR: The string to find in Fatherstr.
Start_position: Represents the starting position of the search from fatherstr . This parameter is optional if omitted by default to 1.
The string index starts at 1. If this parameter is positive, the search starts from left to right, if this parameter is negative, right-to-left,
Returns the starting index of the substring to find in the parent string.
Matchtimes: Represents the number of times a substring is matched in a parent string. This parameter is optional, and if omitted, the default is 1. If the system is negative, it will give an error.

Oracle InStr functions