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SQL Server: the AND and OR Conditions

AND condition and the OR condition

This SQL Server tutorial explains how to use the AND condition and the OR condition together in a SQL Server (Transact-SQL) query with syntax and examples.

Description

The SQL Server (Transact-SQL) AND condition and OR condition can be combined in a SELECT, INSERT, UPDATE, or DELETE statement.

When combining these conditions, it is important to use parentheses so that the database knows what order to evaluate each condition. (Just like when you were learning the order of operations in Math class!)

Syntax

The syntax for the AND condition and the OR conditions together in SQL Server (Transact-SQL) is:

WHERE condition1
AND condition2
...
OR condition_n;

Parameters or Arguments

condition1, condition2, … condition_nThe conditions that are evaluated to determine if the records will be selected.

Note

  • The SQL Server AND & OR conditions allow you to test multiple conditions.
  • Don’t forget the order of operation parentheses!

Example – With SELECT Statement

Let’s look at an example that combines the AND and OR conditions in a SELECT statement.

For example:

SELECT *
FROM employees
WHERE (last_name = 'Anderson' AND first_name = 'Sarah')
OR (employee_id = 75);

This AND & OR example would return all employees whose last_name is ‘Anderson’ and first_name is ‘Sarah, as well as all employees whose employee_id is 75. The parentheses determine the order that the AND and OR conditions are evaluated. Just like you learned in the order of operations in Math class!

The next example takes a look at a more complex statement.

For example:

SELECT employee_id, last_name, first_name
FROM employees
WHERE (last_name = 'Smith')
OR (last_name = 'Anderson AND first_name = 'Sarah')
OR (employee_id > 1000 and state = 'California');

This AND & OR example would return all employee_id, last_name, and first_name values where the last_name is ‘Smith’ OR the last_name is ‘Anderson’ and the first_name is ‘Sarah’ OR the employee_id is greater than 1000 and the state is ‘California’.

Example – With INSERT Statement

This next AND & OR example demonstrates how the AND condition and OR condition can be combined in the INSERT statement.

For example:

INSERT INTO contacts
(last_name, first_name)
SELECT last_name, first_name
FROM employees
WHERE (last_name = 'Johnson' OR 'last_name = 'Anderson')
AND employee_id > 54;

This SQL Server AND and OR example would insert into the contacts table, all last_name and first_name values from the employees table whose last_name is either ‘Johnson’ or ‘Anderson’ and where the employee_id is greater than 54.

Example – With UPDATE Statement

This AND & OR example shows how the AND and OR conditions can be used in the UPDATE statement.

For example:

UPDATE employees
SET last_name = 'TBD'
WHERE employee_id <= 2000
AND (state = 'California' OR state = 'Arizona');

This SQL Server AND & OR condition example would update all last_name values in the employees table to ‘TBD’ where the employee_id is less than or equal to 2000 and resides in either the state of ‘California’ or ‘Arizona’.

Example – With DELETE Statement

Finally, this last AND & OR example demonstrates how the AND and OR conditions can be used in the DELETE statement.

For example:

DELETE FROM employees
WHERE state = 'California'
AND (last_name = 'Johnson' OR first_name = 'Joe');

This SQL Server AND and OR conditions example would delete all records from the employees table where the state is ‘California’ and either the last_name is ‘Johnson’ or the first_name is ‘Joe’.

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