Oracle/PLSQL: INSTR Function
This Oracle tutorial explains how to use the Oracle/PLSQL INSTR function with syntax and examples.
Description
The Oracle/PLSQL INSTR function returns the location of a substring in a string.
Syntax
The syntax for the INSTR function in Oracle/PLSQL is:
INSTR( string, substring [, start_position [, nth_appearance ] ] )
Parameters or Arguments
- string
- The string to search. string can be CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB.
- substring
- The substring to search for in string. substring can be CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB.
- start_position
- Optional. The position in string where the search will start. If omitted, it defaults to 1. The first position in the string is 1. If the start_position is negative, the INSTR function counts back start_position number of characters from the end of string and then searches towards the beginning of string.
- nth_appearance
- Optional. The nth appearance of substring. If omitted, it defaults to 1.
Note: If substring is not found in string, then the INSTR function will return 0.
Applies To
The INSTR function can be used in the following versions of Oracle/PLSQL:
- Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i, Oracle 8i
- See also the REGEXP_INSTR function.
Example
Let's look at some Oracle INSTR function examples and explore how to use the INSTR function in Oracle/PLSQL.
For example:
INSTR('Tech on the net', 'e')
Result: 2 (the first occurrence of 'e')
INSTR('Tech on the net', 'e', 1, 1)
Result: 2 (the first occurrence of 'e')
INSTR('Tech on the net', 'e', 1, 2)
Result: 11 (the second occurrence of 'e')
INSTR('Tech on the net', 'e', 1, 3)
Result: 14 (the third occurrence of 'e')
INSTR('Tech on the net', 'e', -3, 2)
Result: 2