Oracle Database Interview Question:

Can Variables Be Used in SQL Statements?

Submitted by: Administrator

Yes, you can use variables in SQL statements as part of any expressions. The tutorial script provides you some good examples:

(Connect to XE with SQL*Plus)

CREATE TABLE student (id NUMBER(5) PRIMARY KEY,
first_name VARCHAR(80) NOT NULL,
last_name VARCHAR(80) NOT NULL);
Table created.

DECLARE
var_id NUMBER;
var_name CHAR(10);
BEGIN
var_id := 29;
var_name := 'Bob';
INSERT INTO student VALUES(var_id, var_name, 'Henry');
var_name := 'Joe';
INSERT INTO student VALUES(var_id+1, var_name, 'Bush');
var_name := 'ggl';
UPDATE student SET first_name = var_name
WHERE id = var_id+1;
DELETE FROM student WHERE id = var_id;
END;
/

SELECT * FROM student;
<pre>ID FIRST_NAME LAST_NAME
-------- ----------- -----------
30 ggl Bush </pre>
Submitted by: Administrator