The Condition operator is used to create the portion of the Query that the search criteria must meet. The condition operator is the key portion of the SQL Query.
The condition values are as follows:
Equals - The located item will exactly match the search criteria
Does not equal - The located item is anything that does not exactly match the search criteria
Is Like - The located item will contain a portion of the search criteria
Is Not Like - The located item is anything that does not contain a portion of the search criteria
Is Less Than – the numeric item value is less than the criteria
Is Greater Than – the numeric item value is greater than the criteria
Is Null – the located item field is a Null
Is Null – the located item will be any item whose field is not Null
See the topic Using SQL Statements for more information.