Oracle多列单别名

Question

I am trying to select multiple columns and concatenate them in one column with a plus sign and one space on both sides of this plus sign in Oracle 11.2.0.1.0

SELECT ename AS Emplyee_name , deptno AS Department_Number , comm+" + " + sal AS This_Month_Comm_and_sal FROM emp WHERE ename = 'AHMAD';

I am getting this error

ORA-00904: " + ": invalid identifier

same is done in this w3schools tutorial W3schools SQL tutorial

how can I achieve the same result in ORACLE?

Answer 1

The string concatenation operator is || in Oracle: Single quotes must be used here.

SELECT 
    ename AS Emplyee_name , 
    deptno AS Department_Number , 
    TO_CHAR(comm) || ' + ' || TO_CHAR(sal) AS This_Month_Comm_and_sal 
FROM emp 
WHERE ename = 'AHMAD';