如何生成在選擇查詢自動增量場

Question

比如我有2列，first_name和last_name這些值

Ali   Khani 
Elizabette Amini 
Britney  Spears 
,... 

我想寫一個select查詢產生一個像這樣的表的表：

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

感謝您的幫助。

Answer 1

如果它是MySQL中，你可以嘗試

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

SQLFiddle

而對於SQLServer的

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

SQLFiddle

Answer 2

這裏是支持窗口功能的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

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

Answer 4

在這種情況下，你有沒有自然分區值，只是想要一個有序數無關的分區，你可以做一個ROW_NUMBER在一個恆定的，在下面的例子我剛剛使用'X'。 希望這可以幫助別人

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