Posts Tagged with "mysql"

If you ever need to concatenate fields that are empty or equal null, you may run into troubles because MySQL doesn't concatenate NULL-fields as you might expect - if there is one of the concatenating fields equals NULL, the whole concatenating value will be NULL.

See the following dummy table:

firstname | middlename | lastname | email
John        J.           Smith      [email protected]
Amanda      NULL         Smith      [email protected]

As you can see Amanda Smith doesn't have middle name. So, if you now run a query that will try to concatenate first name, middle name and last name, you'll get NULL value instead of expected concatenated value.

Being a web developer, I personally like short solutions, and when I code, I try to write as less code as possible. At the same time the code has to be readable for other developers without using comments.

If you want to combine create/update function into one, MySQL offers you a very useful statement : INSERT ... ON DUPLICATE KEY UPDATE.