可以通过跟随它联合选择吗？

Question

在SQL查询中是否可以在UNION

之后添加order by 1

SELECT * FROM table1 WHERE etc='1' ORDER BY 11;

我们可以在11旁边添加一个联合选择查询吗？

SELECT * FROM table1 WHERE etc='1' ORDER BY 11 UNION select etc etc etc ...;

Answer 1

在MySQL中，您可以在子查询中包含order by子句，并将多个子查询的结果合并在一起;像这样的东西：

SELECT * FROM (SELECT * FROM table1 WHERE etc='1' ORDER BY 11) sq1
UNION ALL
SELECT * FROM (SELECT * FROM table2 WHERE etc='2' ORDER BY 12) sq2
...

Answer 2

也许是这样的：

SELECT 
    *,
    11 AS orderby 
FROM 
    table1 
WHERE 
    etc='1' 
UNION 
select
    *,
    10 AS orderby 
FROM
    table2
ORDER BY
    orderby

Answer 3

您可以这样使用：

SELECT * FROM table1 WHERE etc='1' 
union 
SELECT * FROM table1 WHERE etc='1' 
ORDER BY any_column

Answer 4

您只能在最后ORDER BY之后的查询末尾使用union。基本上所有SELECT都先完成，然后整个结果集被排序。