SQLServerのカーソルタイプ-ローカルカーソルとグローバルカーソルの違いは何ですか。 SQLServerチュートリアル/TSQLチュートリアル

ローカルカーソル：

グローバルカーソル：

--drop table dbo.Customer
Create table dbo.Customer ( 
CustomerId Int ,
CustomerName VARCHAR(100),
StreetAddress VARCHAr(100),
City VARCHAR(100),
State CHAR(2))
go

--Insert few Records in Sample Table
Insert into dbo.Customer
Select 1,'Aamir shahzad','Test Street Address','Charlotte','NC'
Union all
Select 2,'M Raza','Test Street Address','Charlotte','NC'
union all
Select 3,'John Smith','Test Street Address','New York City','NY'
union All
Select 4,'Christy Richard','Test Street Address','Rio Rancho','NM'




--Test with GLOBAL Cursor in Multiple Batches. 
use Test
go

DECLARE Customer_Cursor CURSOR 
--use LOCAL OR GLOBAL HERE
GLOBAL 
FOR
Select CustomerID,
CustomerName,
StreetAddress,
City,
State
from dbo.Customer
OPEN Customer_Cursor;
GO

--Terminate the Batch and change the Database 
use TestDB
go
FETCH NEXT FROM Customer_Cursor
WHILE (@@FETCH_STATUS <> -1)
BEGIN
   FETCH NEXT FROM Customer_Cursor 
   END
CLOSE Customer_Cursor;
GO
DEALLOCATE Customer_Cursor;
GO

We will be able to see the records as we have defined Cursor as GLOBAL and it will be 

available during entire Connection , even we have terminated the first Batch by using GO

statement.

Fig 2: Global Cursor in SQL Server
--Test with LOCAL Cursor in Multiple Batches. 
use Test
go

DECLARE Customer_Cursor CURSOR 
--use LOCAL OR GLOBAL HERE
LOCAL 
FOR
Select CustomerID,
CustomerName,
StreetAddress,
City,
State
from dbo.Customer
OPEN Customer_Cursor;
GO

--Terminate the Batch and change the Database 
use TestDB
go
FETCH NEXT FROM Customer_Cursor
WHILE (@@FETCH_STATUS <> -1)
BEGIN
   FETCH NEXT FROM Customer_Cursor 
   END
CLOSE Customer_Cursor;
GO
DEALLOCATE Customer_Cursor;
GO

As the scope for LOCAL Cursor is limited to Batch, Stored Procedure or Trigger, The second batch is not able to see the Cursor as we have defined LOCAL Cursor type in our above query

--Test with LOCAL Cursor in Multiple Batches. 
use Test
go

Create Procedure Dec_Cursor_Customer AS
BEGIN
DECLARE Customer_Cursor CURSOR 
--use LOCAL OR GLOBAL HERE
GLOBAL 
FOR
Select CustomerID,
CustomerName,
StreetAddress,
City,
State
from dbo.Customer
OPEN Customer_Cursor;
END

GO
Create Procedure Fetch_Cusor_Customer
AS 
BEGIN
FETCH NEXT FROM Customer_Cursor
WHILE (@@FETCH_STATUS <> -1)
BEGIN
   FETCH NEXT FROM Customer_Cursor 
   END
END

--Execute the Procedures to What we get with GLOBAL and LOCAL Cursor Type

EXEC Dec_Cursor_Customer
GO
EXEC Fetch_Cusor_Customer
CLOSE Customer_Cursor;
GO
DEALLOCATE Customer_Cursor;
GO