1. 複製表結構
sql**
1. select * into b from a where 1=0;
select * into b from a where 1=0;
2.複製表記錄 複製某些字段
sql**
1. insert into b(a, b, c) select d, e, f from a;
insert into b(a, b, c) select d, e, f from a;
複製整個表記錄
sql**
1. insert into b select * from a;
insert into b select * from a;
3.外連線查詢
sql**
1. select a.a, a.b, a.c, b.c, b.d, b.f from a left out join b on a.a = b.c;
select a.a, a.b, a.c, b.c, b.d, b.f from a left out join b on a.a = b.c;
4.取特定時間內的資料
sql**
1. select * from a where datediff("minute", 開始時間字段, getdate())>時間差
select * from a where datediff("minute", 開始時間字段, getdate())>時間差
5.兩張關聯表，刪除主表中已經在副表中沒有的資訊
sql**
1. delete from a where not exists(select id from b where a.infid=b.infid );
delete from a where not exists(select id from b where a.infid=b.infid );
6. 複雜的多級條件查詢
sql**
1. select a.num, a.name, b.upd_date, b.prev_upd_date
2. from table1,(select x.num, x.upd_date, y.upd_date prev_upd_date
3. from (select num, upd_date, inbound_qty, stock_onhand
4. from table2
5. where to_char(upd_date,』』yyyy/mm』』) =
6. to_char(sysdate, 』』yyyy/mm』』)) x,
7. (select num, upd_date, stock_onhand
8. from table2
9. where to_char(upd_date,』』yyyy/mm』』) =
10. to_char(to_date(to_char(sysdate, 』』yyyy/mm』』)
11. || 』』/01』』,』』yyyy/mm/dd』』) - 1, 』』yyyy/mm』』) ) y,
12. where x.num = y.num （+）and x.inbound_qty
13. + nvl(y.stock_onhand,0) <> x.stock_onhand ) b
14. where a.num = b.num;
15.
select a.num, a.name, b.upd_date, b.prev_upd_date
from table1,(select x.num, x.upd_date, y.upd_date prev_upd_date
from (select num, upd_date, inbound_qty, stock_onhand
from table2
where to_char(upd_date,』』yyyy/mm』』) =
to_char(sysdate, 』』yyyy/mm』』)) x,
(select num, upd_date, stock_onhand
from table2
where to_char(upd_date,』』yyyy/mm』』) =
to_char(to_date(to_char(sysdate, 』』yyyy/mm』』)
|| 』』/01』』,』』yyyy/mm/dd』』) - 1, 』』yyyy/mm』』) ) y,
where x.num = y.num （+）and x.inbound_qty
+ nvl(y.stock_onhand,0) <> x.stock_onhand ) b
where a.num = b.num;
7.兩個表之間的關聯資料篩選
sql**
1. select * from a
2. where not exists(select id from b where a.id=b.id)
3. and a.a="*"
4. and a.b="*"
5. order by a.c,a.d,a.e;
select * from a
where not exists(select id from b where a.id=b.id)
and a.a="*"
and a.b="*"
order by a.c,a.d,a.e;
sql**
1.
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