This Oracle tutorial explains how to use the Oracle/PLSQL CONCAT function.
CONCAT function concatenates two strings.
The general format for this function is:
CONCAT(string1, string2)
string1 is the first string to concatenate.
string2 is the second string to concatenate.
SQL> SELECT CONCAT('A ', 'B') FROM dual;
CON
---
A B
SQL>
The following example combine two columns together:
-- from w w w.ja v a2s . c o m
CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
ENAME VARCHAR2(10),
JOB VARCHAR2(9),
SAL NUMBER(7, 2),
DEPTNO NUMBER(2));
INSERT INTO EMP VALUES (1, 'SMITH', 'CLERK', 800, 20);
INSERT INTO EMP VALUES (2, 'ALLEN', 'SALESMAN', 1600, 30);
INSERT INTO EMP VALUES (3, 'WARD', 'SALESMAN', 1250.12, 30);
INSERT INTO EMP VALUES (4, 'JONES', 'MANAGER', 2975.23, 20);
INSERT INTO EMP VALUES (5, 'MARTIN','SALESMAN', 1250.23, 30);
INSERT INTO EMP VALUES (6, 'BLAKE', 'MANAGER', 2850, 30);
INSERT INTO EMP VALUES (7, 'CLARK', 'MANAGER', NULL, 10);
INSERT INTO EMP VALUES (8, 'SCOTT', 'ANALYST', 3000, 20);
INSERT INTO EMP VALUES (9, 'KING', 'PRESIDENT',NULL, 10);
INSERT INTO EMP VALUES (10,'TURNER','SALESMAN', 1500, 30);
INSERT INTO EMP VALUES (11,'ADAMS', 'CLERK', 0.99, 20);
SQL> select concat(ename,deptno) from emp;
CONCAT(ENAME,DEPTNO)
--------------------------------------------------
SMITH20
ALLEN30
WARD30
JONES20
MARTIN30
BLAKE30
CLARK10
SCOTT20
KING10
TURNER30
ADAMS20
11 rows selected.
SQL>
CONCAT() is the same as the || operator
SQL> select ename || deptno from emp;
-- w w w . ja v a 2 s .c o m
ENAME||DEPTNO
--------------------------------------------------
SMITH20
ALLEN30
WARD30
JONES20
MARTIN30
BLAKE30
CLARK10
SCOTT20
KING10
TURNER30
ADAMS20
11 rows selected.
SQL>
To concatenate more than 2 strings together, nest multiple CONCAT functions to concatenate more than 2 strings together.
For example, to concatenate 3 strings:
CONCAT( CONCAT( string1, string2 ), string3 )