Mysql Select with concat where some fields are null - mysql

Question

I'm doing a join between two tables to push criteria values into a record description. The problem is some records do not have some/all criteria and the entire string fails:
Select Concat(Description,'<br><br>',C.CritieraNameA,': ',T.CriteriaValueA,'<br><br>',C.CriteriaNameB,': ',T.CriteriaValueB)
From Records T
Inner Join Company C
On T.CompanyID=C.ID
so I end up with
Supermarket specializing in Dairy Products
Hours: 8am-5pmCredit Cards: Yes
and
Gone with the Wind
Running Time: Too long
Format: DVD
This works fine until I hit a record where either
There is no CriteriaTypeA or CriteriaTypeB in the Company Table
There is no CriteriaValueA or CriteriaValueB in the Records Table
Is there a way to do this select so when it doesn' find a CriteriaValue in Records:
Supermarket specializing in Meats
Hours:
Credit Cards: Yes
or a CriteriaName in Company:
Porsche
Type: Sports Car
It does not simply return an empty result?

Answer 1

IfNull could be useful in this case - it will detect a null and replace it with a value you supply.
IFNULL(CriteriaTypeA , "not given")

Answer 2

Concat_WS to the rescue:
Concat_WS('',C.CriteriaTypeA,': ',T.CriteriaValue)

Answer 3

This should do it:
Select Concat(
Description,
Coalesce(Concat('<br><br>',C.CritieraNameA,': ',T.CriteriaValueA), ''),
Coalesce(Concat('<br><br>',C.CriteriaNameB,': ',T.CriteriaValueB), '')
)
From Records T
Inner Join Company C
On T.CompanyID=C.ID
But as I wrote in the comment: Don't implement output logic in SQL.