SQL WHERE Keyword
SELECT
The WHERE command filters a result set to include only records that fulfill a specified condition.
The following SQL statement selects all the customers from "Mexico" in the "Customers" table:
SQL requires single quotes around text values (most database systems will also allow double quotes).
However, numeric fields should not be enclosed in quotes:
Note: The WHERE clause is not only used in SELECT statement, it is also used in UPDATE, DELETE statement, etc.!
The following operators can be used in the WHERE clause:
| Operator | Description |
|---|---|
| = | Equal |
| <> | Not equal. Note: In some versions of SQL this operator may be written as != |
| > | Greater than |
| < | Less than |
| >= | Greater than or equal |
| <= | Less than or equal |
| BETWEEN | Between a certain range |
| LIKE | Search for a pattern |
| IN | To specify multiple possible values for a column |
