CONCAT

Syntax

concat::=

Description of the illustration concat.gif


Purpose

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

In concatenations of two different datatypes, Oracle Database returns the datatype 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 datatype, then the returned value is a national datatype. 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 (||). The function is useful when there are spaces in the values to be concatenated. The concatenation operator does not permit spaces.

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