Join on different tables depending on column data in sql

Question

Is there a way for me to join a table to other tables depending on the data in the cell used in the joining?

I have commented out the code in the join loop to demonstrate how I would want to approach this issue. Basically I want to be able to join one table to either three tables depending on the table name. The column CK_PaymentTableName can only contain either of 3 strings: "PaymentCash", "PaymentBank" or "PaymentCard".

Here is my pseudo code:

select 
    st.ID,
    u.Name,
    st.Comment as Comment
from SalesTable st
    inner join Stuff1 s1 on s1.FK_SalesTableID = st.ID
    inner join Unit u on s1.FK_UnitID = u.UnitID
    --left outer join PaymentBank pba on case 
        --when s1.CK_PaymentTableName = 'PaymentBank' 
        --then pba.PaymentBankID else null end = pba.PaymentBankID
    --left outer join PaymentCard pcc on case 
        --when s1.CK_PaymentTableName = 'PaymentCard' 
        --then pcc.PaymentCardID else null end = pcc.PaymentCardID
    --left outer join PaymentCash pca on case 
        --when s1.CK_PaymentTableName = 'PaymentBank' 
        --then pca.PaymentCashID else null end = pca.PaymentCashID
where 
    st.Derp = 'derp'
group by 
    st.ID, 
    st.Comment, 
    u.Name

Answer 1

Why not Just do an "And" Instead of the CASE? Essentially you dont even need that. Since it is a left Join it will have results if the condition is true.

select 
    st.ID,
    u.Name,
    st.Comment as Comment
from SalesTable st
   inner join Stuff1 s1 on s1.FK_SalesTableID = st.ID
   inner join Unit u on s1.FK_UnitID = u.UnitID
   left outer join PaymentBank pba on s1.CK_PaymentTableName = 'PaymentBank' 
   left outer join PaymentCard pcc on s1.CK_PaymentTableName = 'PaymentCard' 
   left outer join PaymentCash pca on s1.CK_PaymentTableName = 'PaymentCash' 
where 
  st.Derp = 'derp'
group by 
  st.ID, 
  st.Comment, 
  u.Name