sql'select max'查询

Question

我有一个名为“table_name”的表，大概是这样的

+----+-----------+
| ID | title     |
| 1  | title 1   |
| 2  | title 2   |
| ...| ......... |
| ...| ......... |
| n  | title n   |
+----+-----------+.

我需要一个返回此结果的查询

+------+-----------+
| n+1  | title 1   |
| n+1  | title 2   |
| ...  | ......... |
| ...  | ......... |
| n+1  | title n   |
+------+-----------+

（n + 1是从table_name中选择最大值（ID））

我该怎么做？

Answer 1

只需在选择列表中添加子查询：

select (select max(ID) + 1 from tablename), title
from tablename

Answer 2

窗口功能

SELECT MAX(ID) OVER() + 1, title
FROM table_name

Answer 3

您可以为变量选择此最大ID，然后只需在您的选择中使用它：

DECLARE @maxId INT = (SELECT MAX(ID) FROM [dbo].[table1]);
SELECT @maxId, t.title, t.column2, t.column3 ... from [dbo].[table2] t

Answer 4

对于Mysql

select (1+max(ID)) as ID ,title
from table_name;