CONCAT'ing NULL fields
Try
ISNULL(FirstName, '<BlankValue>') -- In SQL Server
IFNULL(Firstname, '<BlankValue>') -- In MySQL
So,
CONCAT(ISNULL(FirstName,''),ISNULL(LastName,''),ISNULL(Email,'')) -- In SQL Server
CONCAT(IFNULL(FirstName,''),IFNULL(LastName,''),IFNULL(Email,'')) -- In MySQL
would return the same thing without the null issue (and a blank string where nulls should be).
Look at CONCAT_WS
For example:
CONCAT_WS('',NULL,"TEST STRING","TEST STRING 2")
Yields
TEST STRINGTEST STRING 2
This is easier than constructing IFNULL
around everything. You can use an empty string as the separator.
In mysql isnull wont work some time. try IFNULL(),
CONCAT(IFNULL(FirstName,''),IFNULL(LastName,''),IFNULL(Email,''))