Using Literal Character Strings in SQL

A concatenation operator :

• Links columns or character strings to other columns
• Is represented by two vertical bars (||)
• Creates a resultant column that is a character expression

Literal Character Strings :

• A literal is a character, a number, or a date that is included in the SELECT statement
• Date and character literal values must be enclosed by single quotation marks
• Each character string is output once for each row returned

Example :

• postgres=# select ename||' earns '||sal as Report from emp;

report
----------------------
SMITH earns 800.00
ALLEN earns 1600.00
WARD earns 1250.00
JONES earns 2975.00
MARTIN earns 1250.00
BLAKE earns 2850.00
CLARK earns 2450.00
SCOTT earns 3000.00
(8 rows)

postgres=#

here as you can see we have added a string "earns" to the two different fields of the table and the displayed result in one single column.

Concatination is done using ||