beacause of a really old db design I need some help. This might be quite simple I'm just not seeing the wood for the trees at the moment.
TABLE A:
ID
1
2
3
4
5
TABLE B:
ID
VALUE B
1
10
1
20
2
10
2
20
3
10
3
20
3
30
4
10
TABLE C:
ID
VALUE C
1
11
1
21
2
11
2
21
2
31
3
11
5
11
Expected result:
where ID = 1
ID
VALUE B
VALUE C
1
10
11
1
20
21
where ID = 2
ID
VALUE B
VALUE C
2
10
11
2
20
21
2
null
31
where ID = 3
ID
VALUE B
VALUE C
3
10
11
3
20
null
3
30
null
where ID = 4
ID
VALUE B
VALUE C
4
10
null
where ID = 5
ID
VALUE B
VALUE C
5
null
11
The entries in table B and C are optional and could be unlimited, the ID from table A is the connection.
B and C are not directly connected. I need a quantitative comparision to find gaps in the database. The number of entries of table B and C should be the same (but not the value), usually entries are missing in either B or C.
I tried it with outer joins but I'm getting two much rows, because I need B or C join only one time per single row.
I hope anybody understand my problem and can help me.
