union all链接三个表
select a,b.. from table1
union all
select a1,b..from table2
union all
select a3,b..from table3
我查询这三个表，现在我想把我所有的查询结果只要2000条，该如何取舍？？？？？？
[解决办法]
try
Select TOP 2000 * From
(
select a,b.. from table1
union all
select a1,b..from table2
union all
select a3,b..from table3) A
[解决办法]
create table table1(
a varchar(10),
b varchar(10)
)
create table table2(
a1 varchar(10),
b varchar(10)
)
create table table3(
a3 varchar(10),
b varchar(10)
)
insert into table1
select 'test1 ', 'test1 ' union all
select 'test2 ', 'test2 '
insert into table2
select 'test3 ', 'test3 ' union all
select 'test4 ', 'test4 '
insert into table3
select 'test5 ', 'test5 '
Select TOP 2000 * From
(
select a,b from table1
union all
select a1,b from table2
union all
select a3,b from table3) A
没问题啊？
[解决办法]
set rowcount 2000
select a,b.. from table1
union all
select a1,b..from table2
union all
select a3,b..from table3
[解决办法]
set rowcount 2000
[解决办法]
Select Top 2000 * From (
Select Top 2000 a,b,... From table1
Union
Select Top 2000 a,b,... From table2
Union
Select Top 2000 a,b,... From table3
) a
這樣寫在一些情況下會好些
