CONCAT

Syntax

Description of the illustration concat.eps

Purpose

CONCAT returns char1 concatenated with char2. Both char1 and char2 can be any of the data types CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. The string returned is in the same character set as char1. Its data type depends on the data types of the arguments.

In concatenations of two different data types, Oracle Database returns the data type that results in a lossless conversion. Therefore, if one of the arguments is a LOB, then the returned value is a LOB. If one of the arguments is a national data type, then the returned value is a national data type. For example:

• CONCAT(CLOB, NCLOB) returns NCLOB

• CONCAT(NCLOB, NCHAR) returns NCLOB

• CONCAT(NCLOB, CHAR) returns NCLOB

• CONCAT(NCHAR, CLOB) returns NCLOB

This function is equivalent to the concatenation operator (||).

See Also:

• Concatenation Operator for information on the CONCAT operator

• Appendix C in Oracle Database Globalization Support Guide for the collation derivation rules, which define the collation assigned to the character return value of CONCAT

Examples

This example uses nesting to concatenate three character strings:

SELECT CONCAT(CONCAT(last_name, '''s job category is '), job_id) "Job" 
  FROM employees 
  WHERE employee_id = 152;
 
Job
------------------------------------------------------
Hall's job category is SA_REP