Oracle / PLSQL: INSTR4 Function

This Oracle tutorial explains how to use the Oracle/PLSQL INSTR4 function with syntax and examples.

Description

The Oracle/PLSQL INSTR4 function returns the location of a substring in a string, using UCS4 code points.

Syntax

The syntax for the INSTR4 function in Oracle/PLSQL is:

INSTR4( string, substring [, start_position [, th_appearance ] ] )

Parameters or Arguments

string

The string to search. string can be CHAR, VARCHAR2, NCHAR, or NVARCHAR2. string can not be 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 INSTR4 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.

Returns

The INSTR4 function returns a numeric value. The first position in the string is 1. If substring is not found in string, then the INSTR4 function will return 0.

Note

• See also the REGEXP_INSTR function.

Applies To

The INSTR4 function can be used in the following versions of Oracle/PLSQL:

• Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i, Oracle 8i

Example

Let's look at some Oracle INSTR4 function examples and explore how to use the INSTR4 function in Oracle/PLSQL.

For example:

INSTR4('aodba.com', 'e')
Output: 2   (the first occurrence of 'e')

INSTR4('aodba.com', 'e', 1, 1)
Output: 2   (the first occurrence of 'e')

INSTR4('aodba.com', 'e', 1, 2)
Output: 9   (the second occurrence of 'e')

INSTR4('aodba.com', 'e', 1, 3)
Output: 11  (the third occurrence of 'e')

INSTR4('aodba.com', 'e', -3, 2)
Output: 9