The WHERE clause is used to extract only those records that fulfill a specified criterion.
Simple SQL WHERE Syntax:
SELECT column_name(s)
FROM table_name
WHERE column_name operator value
Simple WHERE Clause Example
The “Persons” table:
Id | LastName | FirstName | Address | City |
---|---|---|---|---|
1 | Larson | Sue | 3 Cherry | Chicago |
2 | Roberts | Teri | 21 Brown | Chicago |
3 | Peterson | Kari | 30 Mell | Reno |
If you want to select only the persons living in the city “Chicago” from the table above, use the following SELECT statement:
SELECT * FROM Persons
WHERE City='Chicago'
The result-set will look like this:
Id | LastName | FirstName | Address | City |
---|---|---|---|---|
1 | Larson | Sue | 3 Cherry | Chicago |
2 | Roberts | Teri | 21 Brown | Chicago |