Question

例如，我有一个包含2列的表格，first_name和last_name包含这些值

Ali           Khani
Elizabette    Amini
Britney       Spears
,...

我想编写一个select查询，生成如下表：

1     Ali           Khani
2     Elizabette    Amini
3     Britney       Spears
,...

感谢您的帮助。

Answer 1

如果是MySql，你可以尝试

SELECT @n := @n + 1 n,
       first_name, 
       last_name
  FROM table1, (SELECT @n := 0) m
 ORDER BY first_name, last_name

<强> SQLFiddle

对于SQLServer

SELECT row_number() OVER (ORDER BY first_name, last_name) n,
       first_name, 
       last_name 
  FROM table1

<强> SQLFiddle

Answer 2

这里是支持窗口功能的SQL server, Oracle, PostgreSQL。

SELECT  ROW_NUMBER() OVER (ORDER BY first_name, last_name)  Sequence_no,
        first_name,
        last_name
FROM    tableName

SQLFiddle Demo

Answer 3

如果您没有自然分区值并且只想要一个有序数字而不管分区，您可以在常量上执行row_number，在下面的示例中我只使用了＆＃39; X＆＃39 ;。希望这有助于某人

select 
    ROW_NUMBER() OVER(PARTITION BY num ORDER BY col1) as aliascol1, 
    period_next_id, period_name_long
from 
(
  select distinct col1, period_name_long, 'X' as num
  from {TABLE} 
) as x

Answer 4

DECLARE @id INT 
SET @id = 0 
UPDATE cartemp
SET @id = CarmasterID = @id + 1 
GO

如何在选择查询中生成自动增量字段

4 个答案: