游标 cursor 使用方法 循环 取出 单条 信息

CREATE TABLE [dbo].[tb](
 [id] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL,
 [name] [nvarchar](50) COLLATE Chinese_PRC_CI_AS NULL,
 [age] [int] NULL
)

INSERT INTO [tb] ([id],[name],[age]) VALUES (1,a,11)
INSERT INTO [tb] ([id],[name],[age]) VALUES (2,b,22)
INSERT INTO [tb] ([id],[name],[age]) VALUES (3,c,33)
INSERT INTO [tb] ([id],[name],[age]) VALUES (4,d,44)
INSERT INTO [tb] ([id],[name],[age]) VALUES (5,e,55)

declare mc cursor for SELECT [id],[name] ,[age] FROM [tb]
DECLARE @id nvarchar(50)
DECLARE @name nvarchar(50)
DECLARE @age int
open mc
fetch next from mc INTO @id,@name,@age  --先取一次
while @@fetch_status = 0
Begin
select @id,@name,@age --在这做处理

fetch next from mc INTO @id,@name,@age  --循环取

end
 
close mc
deallocate mc