Question

这是我的代码。它贯穿一个公司成立多年的桌子，它应该每年从一行中拉出并打印出来。

  DECLARE @Yearfounded int
--Now I am going to start work on the cursor

DECLARE @YearsCursor CURSOR 
Select [YEar] From dbo.YearsRunning

OPEN YearsCursor

FETCH NEXT FROM YearsCursor into @Yearfounded

WHILE @@FETCH_STATUS = 0

Begin

Print @Yearfounded

Fetch Next From YearsCursor into @Yearfounded

End

Close YearsCursor
Deallocate YearsCursor

这是我得到的错误

Msg 16916，Level 16，State 1，Line 10带有名称的光标＆＃39; YearsCursor＆＃39;不存在。 Msg 16916，Level 16，State 1，Line 14 A. 光标名称为＆＃39; YearsCursor＆＃39;不存在。 Msg 16916，等级 16，状态1，第26行一个名为＆＃39; YearsCursor＆＃39;的光标。才不是存在。消息16916，级别16，状态1，行27具有名称的游标＆＃39; YearsCursor＆＃39;不存在。

Answer 1

如果使用游标变量名：

DECLARE @YearsCursor CURSOR  
SET @YearsCursor  =CURSOR FOR  Select  Select [YEar] From dbo.YearsRunning

或检查语法光标 https://docs.microsoft.com/en-us/sql/t-sql/language-elements/declare-cursor-transact-sql

  DECLARE @Yearfounded int
--Now I am going to start work on the cursor

DECLARE YearsCursor CURSOR FOR Select [YEar] From dbo.YearsRunning

OPEN YearsCursor

FETCH NEXT FROM YearsCursor into @Yearfounded

WHILE @@FETCH_STATUS = 0

Begin

Print @Yearfounded

Fetch Next From YearsCursor into @Yearfounded

End

Close YearsCursor
Deallocate YearsCursor

Answer 2

像这样定义光标

DECLARE YearsCursor CURSOR

Answer 3

 DECLARE @Yearfounded int
--Now I am going to start work on the cursor

DECLARE @YearsCursor CURSOR 
Select [YEar] From dbo.YearsRunning

    OPEN @YearsCursor

FETCH NEXT FROM YearsCursor into @Yearfounded

WHILE @@FETCH_STATUS = 0

Begin

Print @Yearfounded

Fetch Next From YearsCursor into @Yearfounded

End

Close @YearsCursor
Deallocate @YearsCursor

您在打开关闭和取消分配光标时忘记添加@

为什么我的光标会在SQL

3 个答案: