对于 MS SQL SERVER 中的每个？

Question

I have two tables:

Employees(EmployeeID, EmployeeName, EmployeeStatus, BasicSalary) and

EmployeePayroll (PayrollID, EmployeeID, VoucherNo, BasicSalary, SalaryMonth)

I want to make a for each loop for every employee in the first table so that I can insert dummy data like (0, EmployeeID,0,0,0) into the second table.

I tried to make it with a for loop but I could not make it, so is there a for each loop in MS SQL Server??

Answer 1

If you really require a loop, you can use a cursor. They are horribly inefficient , so you should avoid unless you absolutely require it:

DECLARE c CURSOR READ_ONLY FAST_FORWARD FOR
    SELECT EmployeeID
    FROM Employees

DECLARE @id Int

-- Open the cursor
OPEN c

FETCH NEXT FROM c INTO @id
WHILE (@@FETCH_STATUS = 0)
BEGIN
    INSERT INTO EmployeePayroll
    SELECT 0, @id, 0, 0, 0

    -- do other stuff

    FETCH NEXT FROM c INTO @id
END

-- Close and deallocate the cursor
CLOSE c
DEALLOCATE c

Answer 2

Use the following statement:

INSERT INTO EmployeePayroll
SELECT
  0,EmployeeID ,0,0,0
FROM
  Employees

You can check for the existance of the record before inserting it by appending:

WHERE
  ID NOT IN
  (
     SELECT
       EmployeeID
     FROM
       EmployeePayroll
  )

Answer 3

This is the one way to achieve your requirement using While loop & Temp table variable,

The sample query is given below,

--: Get the Employees table data & insert this to temp table variable
Declare @TempEmpTbl Table (RowId int identity, EmployeeID int, EmployeeName nvarchar(100), EmployeeStatus int, BasicSalary int);
Insert into @TempEmpTbl Select * from Employees;

--: temp variables
Declare @TempEmpCount Int = (Select Count(RowId) From @TempEmpTbl);
Declare @MinCount Int = 1;
Declare @GetEmpId int;

--: while loop for EmployeePayroll tbl insertion based on Employees data
While(@TempEmpCount >= @MinCount)
Begin
    Set @GetEmpId = (Select EmployeeID From @TempEmpTbl Where RowId = @MinCount);   
    Insert into EmployeePayroll values (0, @GetEmpId,0 ,0 ,0)
    Set @MinCount = @MinCount + 1;
End

Note: Suppose the employee record is already there, we can able to update EmployeePayroll records from within this while loop.

Answer 4

INSERT INTO EmployeePayroll
SELECT
 0,E.EmployeeID ,0,0,0
FROM
Employees E
WHERE 
NOT EXISTS
(
  SELECT
       1
     FROM
       EmployeePayroll WHERE EmployeeID = E.Id
)

Hope this helps

This is most optimized way to achieve this

Answer 5

I was looking for a decent way for a foreach loop in SQL and came up with this easy code

SELECT RowNum = ROW_NUMBER() OVER(ORDER BY Id),*
INTO #Locations
FROM [dbo].[Location]

DECLARE @MaxRownum INT
SET @MaxRownum = (SELECT MAX(RowNum) FROM #Locations)

DECLARE @Iter INT
SET @Iter = (SELECT MIN(RowNum) FROM #Locations)



WHILE @Iter <= @MaxRownum
BEGIN
DECLARE @currentCountry varchar(250)
DECLARE @locId int
SET @currentCountry = ( SELECT Country 
                        FROM #Locations
                        WHERE RowNum = @Iter)

SET @LocId = (  SELECT Id 
                FROM #Locations
                WHERE RowNum = @Iter)



    -- run your operation here
Update [dbo].[Location]
SET CountryId  = (SELECT (Id) FROM [dbo].[Site] WHERE [dbo].[Site].Name = @currentCountry)
WHERE [dbo].[Location].Id = @locId


    SET @Iter = @Iter + 1
END

DROP TABLE #Locations

Answer 6

Try Cross Apply . This is the best alternate for cursor and looping. Mover over if you compare the execution plan of cross apply with other methods you will notice its noticeably faster

http://sqlserverplanet.com/sql-2005/cross-apply-explained

Answer 7

HI

USE Default constraints for the column which needs to be zero

payrollID,VoucherNo, BasicSalary, Salary-Month

insert the EmployeeID for the same and use the above mentioned concept