SQL AND & OR

The AND/OR operators are used to create an SQL statement based on 2 or more conditions in SQL WHERE clause. They can be used in SELECT, UPDATE, DELETE or INSERT statement.

The AND operator selects records if all the conditions in WHERE clause are true at the same time. The OR operator selects records if any conditions in the WHERE clause are true.

Syntax

SELECT columns
FROM tables
WHERE condition1
     {[AND|OR] condition2}+

The {}+ means that we can repeat it one or more times.

Note: We can indicate the order of the conditions by using the parenthesis sign ().

Examples

Table: Employees

EmployeeId FirstName LastName Department Salary
203 Mazojys Fxoj Finance 78000
204 Jozzh Lnanyo Finance 45800
205 Syllauu Dfaafk Finance 57000
206 Gecrrcc Srlkrt Finance 62000
302 Jssme Bdnaa Development 75000
303 Dnnaao Errllov Development 55000
304 Tyoysww Osk Development 49000

Example 1
We want to select an employee whose first name is Syllauu and last name is Dfaafk:

SELECT *
FROM Employees
WHERE FirstName='Syllauu' AND LastName='Dfaafk'

The result will look like:

EmployeeId FirstName LastName Department Salary
205 Syllauu Dfaafk Finance 57000

Example 2
We want to select employees whose last name is Lnanyo or Bdnaa:

SELECT *
FROM Employees
WHERE LastName='Lnanyo' OR LastName='Bdnaa'

The result will look like:

EmployeeId FirstName LastName Department Salary
204 Jozzh Lnanyo Finance 45800
302 Jssme Bdnaa Development 75000

Example 3
Now we put a little bit more conditions:

SELECT *
FROM Employees
WHERE Department='Finance' AND (LastName='Lnanyo' OR LastName='Bdnaa')

The result will look like:

EmployeeId FirstName LastName Department Salary
204 Jozzh Lnanyo Finance 45800

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>