Join and Group Three Tables On Multiple Criteria - SQL - sql

Question

I am trying to join three separate tables based on certain criteria. Here are table examples:
TABLE A
+----+------------+----------+---------+
| id | entry num | line num | inv line|
+----+------------+----------+---------+
| 1 | 1 | 1 | 1 |
| 2 | 1 | 1 | 2 |
| 3 | 2 | 1 | 1 |
| 4 | 2 | 2 | 1 |
| 5 | 3 | 1 | 1 |
| 6 | 3 | 1 | 2 |
| 7 | 3 | 1 | 3 |
+----+------------+--------+-----------+
TABLE B
+----+------------+----------+---------+
| id | entry num | line num | code |
+----+------------+----------+---------+
| 1 | 1 | 1 | 100 |
| 2 | 2 | 1 | 370 |
| 3 | 2 | 2 | 120 |
| 4 | 3 | 1 | 300 |
+----+------------+--------+-----------+
TABLE C
+----+------------+--------+-----------+
| id | rate | amt | code |
+----+------------+--------+-----------+
| 1 | 25% | $50 | 100 |
| 2 | 50% | $20 | 370 |
| 3 | 50% | $25 | 120 |
| 4 | 30% | $150 | 300 |
+----+------------+----------+---------+
I need the final table to look like this, but I am at a loss on how to write the syntax:
FINAL TABLE
+----+------------+----------+---------+---------+---------+---------+
| id | entry num | line num | inv line| code | rate | amt |
+----+------------+----------+---------+---------+---------+---------+
| 1 | 1 | 1 | 1 | 100 | 25% | $50 |
| 2 | 1 | 1 | 2 | 100 | 25% | $50 |
| 3 | 2 | 1 | 1 | 370 | 50% | $20 |
| 4 | 2 | 2 | 1 | 120 | 50% | $25 |
| 5 | 3 | 1 | 1 | 300 | 30% | $150 |
| 6 | 3 | 1 | 2 | 300 | 30% | $150 |
| 7 | 3 | 1 | 3 | 300 | 30% | $150 |
+----+------------+----------+---------+---------+---------+---------+
Ultimately, I need table A and B joined where both entry num and line num match, but then I need to show each individual row for the inv line number.
For example, entry num 3 / line num 1 will has 3 invoice numbers. All entry num 3/ line num 1 will have the code 300, 30% rate, and $150 amount, but I need to visibly see that there are 3 invoice lines.
I've tried to join tables, group them, and get total counts, but to no avail. Thanks for your help!

Answer 1

I think that you need to create joins between TableA and Table B on EntryNum and LineNum, and then between TableB and TableC on Code. Your SQL should look like:
SELECT A.ID, A.EntryNum, A.LineNum, A.InvLine, B.Code, C.Rate, C.Amt
FROM TableC AS C INNER JOIN (TableB AS B INNER JOIN TableA AS A ON (B.LineNum = A.LineNum) AND (B.EntryNum = A.EntryNum))
ON C.Code = B.Code;
Which produces the result that you want:
Regards,