please give me the complete SQL to make an if-statement (with the field name "T/C") based on the following criteria and add it to the attached code snippet
1. if the field called "cust_ID" is not null in both "table C and table T, then I want the record to say "C/T"
2. if "cust_ID" is null in table C, but not null in table T, then I want it to say "T"
3. if "cust_ID" is null in table T, but not null in table C, then I want it to say "C"
thank you very much
FROM qryConverterTransCustomers_01 AS C RIGHT JOIN (qryConverterTransCustomers_02 AS T RIGHT JOIN tmpMasterTable AS M ON T.cust_ID = M.cust_ID) ON C.cust_ID = M.cust_ID;