Question

i want to create an algorithm or formula that gives me the following combinations below. I have manually printed out all the combinations for the example containing 4 tables with respective values.

This is not permutation because i need the combinations to always follow the unique format

Table1,Table2,Table3,Table4 values

So how can i achieve this in SQL script or through C# code (VB.Net code can also work)

Note: the solution contain all the possible 48 combinations i need for my problem.

Problem

Table1     Table2     Table3    
Table4
a1             b1          
c1             d1
a2             b2          
c2             d2

a3                           
c3
                               
c4

Solution

a1,b1,c1,d1
a1,b1,c1,d2
a1,b1,c2,d1
a1,b1,c2,d2
a1,b1,c3,d1
a1,b1,c3,d2
a1,b1,c4,d1
a1,b1,c4,d2

a1,b2,c1,d1
a1,b2,c1,d2
a1,b2,c2,d1
a1,b2,c2,d2
a1,b2,c3,d1
a1,b2,c3,d2
a1,b2,c4,d1
a1,b2,c4,d2

a2,b1,c1,d1
a2,b1,c1,d2
a2,b1,c2,d1
a2,b1,c2,d2
a2,b1,c3,d1
a2,b1,c3,d2
a2,b1,c4,d1
a2,b1,c4,d2

a2,b2,c1,d1
a2,b2,c1,d2
a2,b2,c2,d1
a2,b2,c2,d2
a2,b2,c3,d1
a2,b2,c3,d2
a2,b2,c4,d1
a2,b2,c4,d2

a3,b1,c1,d1
a3,b1,c1,d2
a3,b1,c2,d1
a3,b1,c2,d2
a3,b1,c3,d1
a3,b1,c3,d2
a3,b1,c4,d1
a3,b1,c4,d2

a3,b2,c1,d1
a3,b2,c1,d2
a3,b2,c2,d1
a3,b2,c2,d2
a3,b2,c3,d1
a3,b2,c3,d2
a3,b2,c4,d1
a3,b2,c4,d2
 

Answer 1

This is called Cartesian product.

select *
from
  table1
  cross join table2
  cross join table3
  cross join table4

Same thing:

select *
from
  table1, table2, table3, table4