Question

你能帮助我吗，我期待输出是，

select * from table order by value

输出：

Value
E1
E2
O
R

必填项：

R
E1
E2
O

Answer 1

试试这个

 SELECT * FROM yourTable
 ORDER BY CASE WHEN VALUE = 'R' Then 1 Else 0 End,Value ASC

如果您使用的是UNION，请尝试使用

SELECT * FROM
(
  SELECT * 
    FROM table1
   UNION ALL
  SELECT *
    FROM table2
) T
ORDER BY CASE WHEN VALUE = 'R' Then 1 Else 0 End,Value ASC

Answer 2

有点黑客但如果这就是你想要的......

order by 
case when value='r' then 1
    when value='e1' then 2
    when value='e2' then 3
    when value='o' then 4 end

Answer 3

尝试

SELECT * 
  FROM table1
 ORDER BY CASE 
            WHEN value = 'R'     THEN 0
            WHEN value LIKE 'E%' THEN 1
            WHEN value = 'O'     THEN 2 
          END, LEN(value), value

输出：

| VALUE |
|-------|
|     R |
|    E1 |
|    E2 |
|     O |

这是 SQLFiddle 演示

...如果我使用union all运算符合并两个表，则显示错误...

使用UNION即可

SELECT *
  FROM
(
  SELECT * 
    FROM table1
   UNION ALL
  SELECT *
    FROM table2
) q
 ORDER BY CASE 
            WHEN value = 'R'     THEN 0
            WHEN value LIKE 'E%' THEN 1
            WHEN value = 'O'     THEN 2 
          END, LEN(value), value

如何使用order by得到输出？

3 个答案: