sql 运用union出現問題

sql 使用union出現問題

SQL code

select a,b,c into #tb from table union select a,b,c into #tb2 from table2

union前後的語句都可以單獨運行，但是加上union一起的話就報錯；

錯誤提示：SELECT INTO must be the first query in a statement containing a UNION, INTERSECT or EXCEPT operator.



[解决办法]

SQL code

select a,b,c into #tb from table select a,b,c into #tb2 from table2select * from #tbunionselect * from #tb2
[解决办法]
select a,b,c into #tb from table 是创建表并且插入数据，并不是查询结果

而union 是取那个结果集的并集 ，所以不能这样写
[解决办法]
SQL code
select a,b,c into #tb from table select a,b,c into #tb2 from table2select * from #tbunion all --不过滤重复数据了select * from #tb2
[解决办法]
不能带着into 进行 union。