MySQL fixed allowed combinations from multiple tables - mysql

Question

I am designing a database to organize materials for 3D production.
Materials are named like 1_Fabric_01_Textile_001_BlueJeans_Denim and 2_Metal_02_BrushedMetal_002_ChromeBrushed_Chrome, etc
So, I need a materials table, which basically has information on material name (last value, look above) and a combination of type and subvariant. Each type has allowed variants like 1_Fabric has 01_Textile, 02_Leather, 2_Metal has 01_Metal, 02_BrushedMetal and so on.
Now making all combinations would not be difficult (i.e., being able to choose every possible subvariant for every material type), but I want to limit the combinations to only allowed combinations, so users cannot choose invalid combinations (like 1_Fabric_01Metal or 2_Metal_01Textile).
Any ideas?

Answer 1

In order to generate those kind of name
1_Fabric_01_Textile
2_Metal_02_BrushedMetal
Based on the followin tables
Type
----------
Id Name
-- ------
1 1_Fabric
2 2_Metal
SubType
------------
Id Name
-- ------
1 01_Textile
2 02_Leather
3 01_Metal
4 02_BrushedMetal
And keeping rules on what types can relate to subtypes
You ill need a relational table like:
Type_SubType
-----------------
TypeId SubTypeId
------ ---------
1 1
1 2
2 3
2 4
and if you need more levels of subtypes you can add more tables
1_Fabric_01_Textile_001_BlueJeans_Denim
2_Metal_02_BrushedMetal_002_ChromeBrushed_Chrome
SubSubType
--------------
Id Name
-- ----------
1 001_BlueJeans_Denim
2 002_ChromeBrushed_Chrome
Type_SubType_SubSubType
-------------------------
TypeId SubTypeId SubSubType
------ --------- ----------
1 1 1
2 3 2
Now the trick part is to do a better normalization for the third level relation. It can be achieved if you add a identity column to the first relational table
So instead you can use this example:
Type_SubType
---------------------
Id TypeId SubTypeId
-- ------ ---------
1 1 1
2 1 2
3 2 3
4 2 4
and relating it to the second relational table
Type_SubType_SubSubType
-------------------------
Type_SubTypeId SubSubType
-------------- ----------
1 1
3 2
to retrieve only the possible matches is trivial
select * from type tp
join Type_SubType tp_sb on tp_sb.TypeId = tp.Id
join SubType sb on sb.Id = yb_sb.SubTypeId
or just (if you already selected a type and put it in the variable #TypeId)
Select * from SubType sb
join Type_SubType tp_sb on tp_sb.SubTypeId = sb.Id
where tp_sb.TypeId = #TypeId
and so on for SubSubTypes
note: this solutions only covers a fixed (or maxed) number of sub-sub. To get a total dynamic level of abstractions you ill need a recursive FK. Not something like rocket science but if you still the basics on SQL try stick with the most simple example.