![]() ![]() Once you start using more conditions, you should use parentheses to surround the conditions that you want to be evaluated first. If you have multiple conditions, you can use multiple operators (whether both the same operators or different). ![]() For example, if we wanted to get information about all owners whose first name is not Homer, we could do the following: SELECT * When comparing with a string value, use quotes around the string. The query returns all owners except owner number 3. Our query uses the not equal to operator ( !=) to test whether the OwnerId column is not equal to 3. If we wanted to return a list of all owners that do not have an OwnerId of 3, we could do this: SELECT * | OwnerId | FirstName | LastName | Phone | Email | This is the table we will use for the examples on this page. Imagine our database contains the following table. Which one you use may depend on your DBMS, which one you’re the most comfortable using, and perhaps also whether your organisation has any coding conventions that dictate which one should be used. SQL also has another not equal to operator ( ), which does the same thing. If either or both operands are NULL, NULL is returned. That is, it tests whether one expression is not equal to another expression. In SQL, the not equal to operator ( !=) compares the non-equality of two expressions. ![]()
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