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union All orDEr By

您好,我来为您解答: select a,b,c,d from (select t1.a,t1.b,t1.c from t1 where t1.e = ' ' union all select t2.a,t2.b,t2.c from t2 where t2.e = ' ') order by a order by的优先级比union all 要低,因此如果有union ,会先执行union,再...

select t.* from(select xx,yy,zz from t1union allselect xx,yy,zz from t2union all……) torder by 字段

union和order by连用需要放在子查询中,否则会报错 例如: 错误写法: select * from dept1 order by deptno union select * from dept2 order by deptno; ORA-00933 "SQL command not properly ended" 正确写法: select * from (select * from...

select * from ( select u.*, r.statusname, p.*, c.* from UserLogin U, RepairStatus R, Product P, Customer C where U.status = R.statusid and U.ProductName = P.ProductName and U.BoatName = C.BoatName and U.RepairDate

在SQL语句中,UNION关键字多用来将并列的多组查询结果(表)合并成一个结果(表),简单实例如下: SELECT [Id],[Name],[Comment] FROM [Product1] UNION SELECT [Id],[Name],[Comment] FROM [Product2] 上面的代码可以实现将从Product1和Product2两...

(select top 9 * from table1 order by id) union (select top 19 * from table2 order by id) union (select top 99 * from table3 order by id) 你如果想union之后再order by的话得使用子查询

可行 但是你必须把每个结果集保存在子查询中。 如: SELECT * FROM (SELECT '002', '语文', '' FROM DUAL ORDER BY 1) UNION ALL SELECT * FROM (SELECT '001', '数学', '' FROM DUAL ORDER BY 1) UNION ALL SELECT * FROM (SELECT '003', '英语...

在前面在加一列,然后把union all 的结果放到子查询中,用来排序 比如: select * from (select 0+a ord,t.* from where a is not null union all select 1+b ord,t.* from where a is not null ) ta order by ord

order by只能用于外部查询中,不能应用于子查询中。 上面的sql,union all合并了2个sql查询结果集,order by当成union all合并结果集的排序,但是结果集中无表a和字段bqdm。 select * from (select a.bqdm,sum(a.zyrs) 今日在院人数 from YZCX_Y...

因为union all是将来年各个查询的结果集拼接在一起, 你如果在其中的一个查询中order by,没记错的话会语法错误,假设没语法错误的话, 只是对结果集的一部分进行排序,不能达到对整个结果集进行排序的效果,所以是没有意义的 如果你想实现对整...

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