SQL WHERE Clause

WHERE Syntax

SELECT column1, column2, …
FROM table_name
WHERE condition

Note: The WHERE clause is used in the following statements: SELECT, UPDATE, DELETE, etc…


Demo Database

Below is a selection taken out of the “Customers” table in the Northwind database:

WHERE Clause Example

The following SQL statement selects all the customers from the country “Mexico”, in the “Customers” table:

Example

SELECT * FROM Customers
WHERE Country=’Mexico’;

Text Fields vs. Numeric Fields

SQL needs single quotes around text values (most database systems will also allow double quotes).

However, numeric fields should not have quotes around them.

Example

SELECT * FROM Customers
WHERE CustomerID=1;

Operators in The WHERE Clause

The following operators can be used in the WHERE clause: