Suppose we have three tables:
Table 1
| c_id | categories | |-------------------|------------------| | 7 | a | | 4 | b | | 3 | c |
Table 2
| c_id | dup_id | |-------------------|--------------| | 9 | 10 | | 5 | 3 | | 6 | 2 |
table 3
| c_id | description | |-------------------|--------------| | 22 | xxxx | | 5 | yyyy | | 11 | zzzz |
Suppose if some values in dup_id
in Table1 are equal to dup_id
in Table2, then we can find the dup_id# corresponding to
dup_id ##, and use it to find
description in Table3. What's the best way to do this?
Output:
| c_id | description | |-------------------|--------------| | 5 | yyyy |
P粉2880690452024-04-04 14:26:03
It seems to be a direct connection of 3 tables:
select Table2.c_id, description from Table1 join Table2 on Table1.c_id = Table2.dup_id join Table3 on Table2.c_id = Table3.c_id;