SET

MySQL

Example

SET @name = 'John Doe';
SELECT @name;

Output

+-----------+
| @name     |
+-----------+
| John Doe  |
+-----------+

Explanation

The SET command in the SQL statement is used to assign a value to the variable @name. The SELECT command is then executed to display the value of the @name variable, which in this case is ‘John Doe’.

PostgreSQL

Example

SET timezone TO 'America/New_York';
SHOW timezone;

Output

    TimeZone
---------------------------
 America/New_York

Explanation

The SET statement is used to change the current setting of a run-time configuration option for the duration of the current session. The example above is changing the timezone to ‘America/New_York’. The SHOW command is displaying the current set timezone.

SQL Server

Example

DECLARE @TestVariable INT;
SET @TestVariable = 5;
SELECT @TestVariable;

Output

5

Explanation

The variable @TestVariable is declared to be of type INT. Subsequently, the SET statement assigns the value 5 to @TestVariable. The SELECT statement then retrieves the value, outputting 5.

Oracle

Example

SET SERVEROUTPUT ON
DECLARE
   test_variable NUMBER(2);
BEGIN
   test_variable := 15;
   dbms_output.put_line('The value of test_variable is ' || test_variable);
END;
/

Output

The value of test_variable is 15

Explanation

In the example code, the SERVEROUTPUT feature of SQL*PLUS is enabled with the SET SERVEROUTPUT ON command. This allows the DBMS_OUTPUT.PUT_LINE to function. Within a PL/SQL block, a variable named test_variable of NUMBER type is declared and set to 15. The dbms_output.put_line command prints the appended string and the value of test_variable which gives us our output.