Sql 如何根据列选择多行
因此,我在Oracle数据库中有两列:Sql 如何根据列选择多行,sql,oracle,row-number,Sql,Oracle,Row Number,因此,我在Oracle数据库中有两列: Name / count 我想把名字打印x次,x是计数 E.g. Paul / 5 would mean Paul being printed 5 times. Sam / 6 would mean Sam being printed 6 times 尝试了行数,但不确定它是如何工作的?您需要递归查询来实现这一点 with cte(nam, ctr) as ( select 'Paul' as nam, 5 as ctr from d
Name / count
我想把名字打印x次,x是计数
E.g. Paul / 5 would mean Paul being printed 5 times.
Sam / 6 would mean Sam being printed 6 times
尝试了行数,但不确定它是如何工作的?您需要递归查询来实现这一点
with cte(nam, ctr) as (
select 'Paul' as nam, 5 as ctr from dual
union all
select 'Sam', 6 as ctr from dual
),
cte2(nam, ct, ctr) as (
select nam, 1 as ct, ctr from cte
union all
select nam, ct + 1, ctr from cte2
where ct<ctr
)select nam, ct from cte2
order by nam asc
输出:
请参见您可以通过以下方式使用连接:
SQL> WITH YOUR_TABLE AS
2 (SELECT 'paul' as NAME, 5 AS COUNT FROM DUAL UNION ALL
3 SELECT 'sam' as NAME, 6 AS COUNT FROM DUAL
4 ) -- YOUR ACTUAL QUERY STARTS FROM LINE#5
5 Select t.name, m.lvl
6 from your_table t
7 join
8 (Select level as lvl
9 from
10 (Select max(count) as maxcount
11 from your_table)
12 Connect by level <= maxcount) m
13 On (t.count >= m.lvl)
14 ORDER BY 1,2;
NAME LVL
---- ----------
paul 1
paul 2
paul 3
paul 4
paul 5
sam 1
sam 2
sam 3
sam 4
sam 5
sam 6
11 rows selected.
SQL>
干杯 这将起作用:
select name
from Table1,
(select level lvl
from dual
connect by level <= (select max(cnt) from Table1 )
)
where lvl <= cnt
order by name;
检查小提琴:
谢谢 您的查询从第4行开始的另一个选项:
SQL> with your_table as
2 (select 'paul' as name, 5 as count from dual union all
3 select 'sam' as name, 6 as count from dual)
4 select name
5 from your_table cross join table (cast (multiset (select level from dual
6 connect by level <= count
7 ) as sys.odcinumberlist));
NAME
----
paul
paul
paul
paul
paul
sam
sam
sam
sam
sam
sam
11 rows selected.
SQL>
您可以使用逐级连接,谢谢!它工作得很好,但似乎与我的代码的其余部分不太匹配。我有一个很大的代码,我想在任何其他建议中插入这一位?我需要查看您的代码,生成N行的唯一方法是使用cte,for循环或游标。
with tab(Name,"count") as
( select 'Paul', 5 from dual union all select 'Sam', 6 from dual )
select name, level as seq
from dual d
cross join tab t
connect by level <= t."count"
and prior name = name
and prior sys_guid() is not null;