We already check for empty value, remove todo

Signed-off-by: Michal Čihař <michal@cihar.com>
Simplify setting collation connection

Signed-off-by: Michal Čihař <michal@cihar.com>
Check for correct return type

Signed-off-by: Michal Čihař <michal@cihar.com>
Fix type string for longtext

It has to be checked before "long", otherwise it matches first.

Signed-off-by: Michal Čihař <michal@cihar.com>