Declaring cursor to loop over some values in SQL Server 2008 R2

Question

I have some business unit such as India, International, US, UK.

I have to:

1. Create a table variable (virtual in-memory table) with columns that match stored procedure SP_Report resultset
2. Declare a cursor that contains all business units and then the cursor should loop over the BU's
3. For each BU, execute a stored procedure called SP_Report and insert the data into the table variable
4. Finally I have to select the columns from the table variable + timestamp + BU, insert them into another table and clear the table variable.

Code:

declare @K table (BU nvarchar(max), K nvarchar(max),Y money, A money, D money, YP money)
declare @FY int
declare @BU nvarchar(max)

INSERT INTO @K (BU, K, Y, A, D, YP) 
    EXEC dbo.SP_Report '2012', 'India'

SELECT * FROM @K

This code returns the result of the table variable. Now I have to use it cursor, which I don't know how to. How I can solve the same.

Answer 1

The MSDN/BOL topic for DECLARE CURSOR contains example syntax for cursor usage. That said, as I had 5 minutes to spare on the train this morning...

-- Create temporary table for Business Units (replace with the "real" table)
DECLARE @BusinessUnit TABLE (BU NVARCHAR(MAX))

INSERT @BusinessUnit
SELECT 'India' UNION SELECT 'International' UNION SELECT 'US' UNION SELECT 'UK'

DECLARE @K TABLE (BU NVARCHAR(MAX),K NVARCHAR(MAX),Y MONEY,A MONEY,D MONEY,YP MONEY)
DECLARE @FY INT
DECLARE @BU NVARCHAR(MAX)

SET @FY = 2012

DECLARE BU_cursor CURSOR FAST_FORWARD FOR
SELECT BU FROM @BusinessUnit

OPEN BU_cursor
FETCH NEXT FROM BU_cursor INTO @BU

WHILE @@FETCH_STATUS = 0
BEGIN
    INSERT @K (BU, K, Y, A, D, YP)
    EXEC dbo.SP_Report @FY, @BU

    FETCH NEXT FROM BU_cursor INTO @BU
END

CLOSE BU_cursor
DEALLOCATE BU_cursor

SELECT * FROM @K

Answer 2

Can you take this one step further and make the inner query run dynamic sql, something like this:

DECLARE @BusinessUnit TABLE (BU NVARCHAR(MAX))
DECLARE @cmd varchar(222)
INSERT @BusinessUnit
SELECT 'India' UNION SELECT 'International' UNION SELECT 'US' UNION SELECT 'UK'

--DECLARE @K TABLE (BU NVARCHAR(MAX),K NVARCHAR(MAX),Y MONEY,A MONEY,D MONEY,YP MONEY)
DECLARE @FY INT
DECLARE @BU NVARCHAR(MAX)

SET @FY = 2012

DECLARE BU_cursor CURSOR FAST_FORWARD FOR
SELECT BU FROM @BusinessUnit

OPEN BU_cursor
FETCH NEXT FROM BU_cursor INTO @BU
WHILE @@FETCH_STATUS = 0
BEGIN
DECLARE @K TABLE (BU NVARCHAR(MAX),K NVARCHAR(MAX),Y MONEY,A MONEY,D MONEY,YP MONEY)
    --INSERT @K (BU, K, Y, A, D, YP)
    --EXEC dbo.SP_Report @FY, @BU

    SET @cmd = 'INSERT '+@K+' (BU, K, Y, A, D, YP)'+
    ' SELECT '+@BU+','+@BU+',456,78,99,11111'
    EXEC sp_sqlexec @cmd
    FETCH BU_cursor INTO @BU
END
CLOSE BU_cursor
DEALLOCATE BU_cursor

SELECT * FROM @K

Answer 3

I think, its the best example to understand CURSOR easily..

Using Cursor in SQL Server

Answer 4

simple example to understand cursors:

DECLARE @CustomerID as INT;
declare @msg varchar(max)
DECLARE @BusinessCursor as CURSOR;

SET @BusinessCursor = CURSOR FOR
SELECT CustomerID FROM Customer WHERE CustomerID IN ('3908745','3911122','3911128','3911421')

OPEN @BusinessCursor;
    FETCH NEXT FROM @BusinessCursor INTO @CustomerID;
    WHILE @@FETCH_STATUS = 0
        BEGIN
            SET @msg = '{
              "CustomerID": "'+CONVERT(varchar(10), @CustomerID)+'",
              "Customer": {
                "LastName": "LastName-'+CONVERT(varchar(10), @CustomerID) +'",
                "FirstName": "FirstName-'+CONVERT(varchar(10), @CustomerID)+'",    
              }
            }|'
        print @msg
    FETCH NEXT FROM @BusinessCursor INTO @CustomerID;
END