Question

I have a lookup table

Tbl_UserType_value_lookup:

UserTypeID  |AllowedValue
-------------------------
1           |x
1           |y
2           |u
3           |a

(This says an user of Type 1 can enter the values of type x and y only and not of type u or a..so on)

I have another table

Tbl_Activity:

UserID   |userTypeID    |value
---------------------------

Now in this table how can I resrtict a user of type 1 to the values as per Tbl_UserType_value_lookup table using CHECK constraint ?

Is there any other way?

Answer 1

Assuming that you have a unique key on Tbl_UserType_value_lookup for UserTypeID, Allowed Value, you could have a composite foreign key on Tbl_Activity that references these columns.

(ie the combination of UserType, Value would have to exist on Tbl_UserType_value_lookup to be insertable.

There’s quite a lot of discussion of this here:

Creating a composite foreign key in SQL Server 2008