The SQL WHERE Clause
The WHERE clause is used to filter records.
It is used to extract only those records that fulfill a specified condition.
WHERE Syntax
SELECT column1, column2, ...
FROM table_name
WHERE condition;Note: The WHERE clause is not only used in SELECT statements, it is also used in UPDATE, DELETE, etc.!
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 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;