In which conditions, MySQL CASE statement return NULL?

Home Questions Tags Users Unanswered.

SQL CASE Statement

You can't delete other events. In MySQL, decode is a deprecated cryptographic function. These aggregations are not exactly the ones we wanted. Development Versions: Ten Centuries. In SQL Null is both a value as well as a keyword. Copyright by Refsnes Data. Post as a guest Name. This is similar to the switch statement in C. Leave a Reply Cancel reply Enter your comment here You can't delete your own events.


Nevertheless there are cases that can lead to surprising side effects. Matt Miller 4 Posted 11 years ago There will be cases when we will have to perform computations on a query result set and return the values. Will schedule another blog post: Stack Overflow works best with JavaScript enabled. But in fact, the improvement is really easy. Privacy Policy. As usual, null is special: You can't edit your own events.

As described in Section 4.

MySQL :: CASE Statement Checking Null

You can't post or upload images. Page address: Joe Doherty A guide to database performance for developers. In order to avoid such situations from happening, we can employ the use of the NOT NULL clause to limit the results on which our data operates.

The undefined evaluation process can have unpredictable side effects.