wy
发帖数: 14511 | 1 3 tables:
a key(id)
b a_id, c_id
c key(id)
b.a_id and c_id point to a and c respectively.
Now, given c_id, I want to select all a where b.c_id = given c_id, but
only with the latest ones. id is auto increment, so "the latest" means
id being the largest. for example,
I have a(1), I have b(a_id = 1, c_id =1) and b(a_id=2, c_id = 2)
If given c_id =1, the query should *not* return a(1), but
given c_id = 2, the query should reutn a(1) | s***i
发帖数: 6149 | 2
what does the query return in these two cases then? don't
understand the logic..
【在 wy 的大作中提到】
: 3 tables:
: a key(id)
: b a_id, c_id
: c key(id)
: b.a_id and c_id point to a and c respectively.
: Now, given c_id, I want to select all a where b.c_id = given c_id, but
: only with the latest ones. id is auto increment, so "the latest" means
: id being the largest. for example,
: I have a(1), I have b(a_id = 1, c_id =1) and b(a_id=2, c_id = 2)
: If given c_id =1, the query should *not* return a(1), but
| wy
发帖数: 14511 | 3 never mind, solved.
【在 s***i 的大作中提到】
:
: what does the query return in these two cases then? don't
: understand the logic..
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