Welcome to Lesson 2 of the TSQL Tutorial. In this lesson we will cover where clauses. I hope you enjoy the lesson.
Select Statements
WHERE
The WHERE
command is used to specify a selection criteria.
Usage:
SELECT column(s)
FROM table
WHERE criteria
Example: We want to select only those employees that live in the city London
(Note: we use single quotes around 'London' because it is a text field.
Text fields will be highlighted in red for readability.)
SELECT *
FROM employees
WHERE city = 'London'
Results:
|
EmployeeID
|
LastName
|
FirstName
|
Title
|
BirthDate
|
HireDate
|
Address
|
City
|
|
5
|
Buchanan
|
Steven
|
Sales
Manager
|
3/4/1955
|
10/17/1993
|
14 Garrett
Hill
|
London
|
|
6
|
Suyama
|
Michael
|
Sales
Representative
|
7/2/1963
|
10/17/1993
|
123 Miner
Rd.
|
London
|
|
7
|
King
|
Robert
|
Sales
Representative
|
5/29/1960
|
1/2/1994
|
Edgeham
Hollow
|
London
|
|
9
|
Dodsworth
|
Anne
|
Sales
Representative
|
1/27/1966
|
11/15/1994
|
7
Houndstooth Rd.
|
London
|
Example2:Suppose we want employees that live in London and also has manager in their
title.
(Note that operator commands such as "AND" and "LIKE" are shown in gray.)
(Note: % is a wildcard character, we want any title that has the word manager)
SELECT *
FROM Employees
WHERE (City = 'London') AND (Title LIKE '%Manager%')
Results:
|
EmployeeID
|
LastName
|
FirstName
|
Title
|
BirthDate
|
HireDate
|
Address
|
City
|
|
5
|
Buchanan
|
Steven
|
Sales
Manager
|
3/4/1955
|
10/17/1993
|
14 Garrett
Hill
|
London
|