Filtering Data

In most cases, we will not want every single row in the table and we need a way to identify which rows we want returned. We can add a filter to the query and limit the rows returned. While performance tuning is beyond the scope of this book, you would be surprised at...

Special Filter Operators

LIKE  Let‘s say we‘re looking for a cat, but couldn’t quite remember its name; however, we know it started with Gar. We can use the LIKE operator to help us find the list of names that start with Gar. We should only use the LIKE operator with text data types. ...

Filtering Groups with Having

Just as we use the WHERE clause to limit the records returned, we can limit the groups returned, if they don’t meet a specific criteria, using the keyword HAVING. HAVING will not remove rows from being eligible in our result; however, it will remove groups that don’t...