1.select top 10 * from sysdepends2.select * from (select top 10 * from sysdepends)n3.select id from (select top 10 * from sysdepends)n
1和2的结果都一样,为什么3查询出来的ID列的数据与1,2查询出来的ID列的数据不同?
1和2的结果都一样,为什么3查询出来的ID列的数据与1,2查询出来的ID列的数据不同?
下面是select top 10 * from sysdepends的id列的数据
id
101575400
101575400
229575856
229575856
1961058022
1961058022
1961058022
1961058022
1961058022
101575400
下面是select id from (select top 10 * from sysdepends)n 的id列的数据
id
1
1
1
1
1
1
1
1
1
1
select top 10 * from sysdepends
order by idselect * from (select top 10 * from sysdepends order by id)n
select id from (select id from sysdepends order by id)n
3.select id from (select top 10 * from sysdepends)n 可能转换为:select top 10 id from sysdepends来执行了