(SQL) WHERE: Specifying Conditions

The WHERE clause is used to filter records. It is used to extract only those records that fulfill a specified condition and usually follows a SELECT expression.

Example

Select all customers from Mexico:

SELECT * FROM Customers
WHERE Country='Mexico';

Text Fields vs. Numeric Fields

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

However, numeric fields should not be enclosed in quotes:

Example

SELECT * FROM Customers
WHERE CustomerID=1;

Operators in The WHERE Clause

You can use other operators than the = operator to filter the search.

Example

Select all customers with a CustomerID greater than 80:

SELECT * FROM Customers
WHERE CustomerID > 80;

The following operators can be used in the WHERE clause: