Using Variables in Syntax

Question

We are in the process of consolidating all data.  We have consolidated all our timekeeping/payroll data, but unfortunately the bulk of sale data still exists in tables based off store numbers.  I am needing to get a list of all employees who worked
on Black Friday (Nov 28) and take a look at their sales.  I took this in a two step approach one, get a list of all employees who had a clockin date of 11/28/2014 and insert them into a table, then step 2 I was going to iterate each employee from that
table and insert sale #'s into a second table, and query the final results of the 2nd table to show full circle.  Problem, I keep getting an error of 'Invalid Column Name 'Employee''  
Below is my syntax...speed is critical for me, so if there is a faster way of achieving these same results please let me know.  SQL Server 2008 is the server I am running this on.
Create Table #EmployeesWhoWorked (ID Int Identity, storeNum int)
Create Table #Results (empName, StoreNum int, empitemSold int, emptotalSold int)
--This works
Insert Into @EmployeesWhoWorked (storeNum)
Select storeNum
From timekeeping
Where clockindate = '11/28/2014'
--This is the piece that errors
Declare @N int, @Str Nvarchar(4000), @storeNum varchar(1000), @MaxID int)
Set @N = 1
Select @MaxID = Max(ID)
FROM #EmployeesWhoWorked
While (@N<=@MaxID)
Begin
Select @storeNum = storeNum
FROM #EmployesWhoWorked
Where ID = @N
Set @Str =
' Insert Into #Results (empName, StoreNum, empitemSold, emptotalSold)
Select empName, '+@StoreNum+', Count(itemSold), SUM(itemvalues)
From '+@StoreNum+'
WHERE clockindate = '11/28/2014'
Exec SP_ExecuteSQL @Str
Set @N = @N + 1
End
Select *
FROM #Results

Answer 1

E.g.
CREATE TABLE #EmployeesWhoWorked
ID INT IDENTITY ,
storeNum INT
CREATE TABLE #Results
empName VARCHAR(1000) ,
StoreNum INT ,
empitemSold INT ,
emptotalSold INT
DECLARE @clockindate DATE = '20141128';
INSERT INTO #EmployeesWhoWorked
( storeNum
SELECT storeNum
FROM timekeeping
WHERE clockindate = @clockindate;
DECLARE @N INT ,
@Str VARCHAR(MAX) ,
@storeNum INT ,
@MaxID INT;
SET @N = 1;
SELECT @MaxID = MAX(ID)
FROM #EmployeesWhoWorked;
DECLARE @SQL VARCHAR(MAX);
SET @SQL = '
INSERT INTO #Results
( empName ,
StoreNum ,
empitemSold ,
emptotalSold
SELECT empName ,
@storeNum ,
Count(itemSold) ,
SUM(itemvalues)
FROM @TableName
WHERE clockindate = @clockindate;
WHILE ( @N <= @MaxID )
BEGIN
SELECT @storeNum = storeNum
FROM #EmployesWhoWorked
WHERE ID = @N;
SET @Str = REPLACE(@SQL, '@TableName', QUOTENAME(CAST(@storeNum AS VARCHAR(255))));
EXEC sp_executesql @Str, '@storeNum INT, @clockindate DATE', @storeNum, @clockindate;
SET @N = @N + 1;
END;
SELECT *
FROM #Results;
But I don't understand your loop approach..