| Operator | Description |
| = | Equal |
| <> or != | Not equal |
| < | Less than |
| > | Greater than |
| <= | Less than or equal |
| >= | Greater than or equal |
| ANY | Compares one value with any value in a list |
| ALL | Compares one value with all values in a list |
hmetic operator
Comparison Operator
There are many comparison operators that you can use in a WHERE clause:
The following table lists the comparison operators:
Logical Operator
Null Values
Variable
Comments
Terminology
Database Normalization
原文：http://www.cnblogs.com/daishuguang/p/4059985.html