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 |