WHERE clause specifies how the data being retrieved must be constrained.
The syntax is as follows:
<constraint> is an expression for which the value always equals true. Expressions consist of simple comparisons using operators, functions, keywords or system variables.
For more information, see OQL Expressions.
This query retrieves all customers whose name is equal to “Jansen”:
SELECT FirstName FROM Sales.Customer WHERE LastName = 'Jansen'
This query retrieves all customers who live in “Rotterdam”:
SELECT FirstName FROM Sales.Customer INNER JOIN Sales.Customer/Sales.Customer_Address/Sales.Address WHERE Sales.Address/City = 'Rotterdam'