Loop and Temp Table usage in SQL SERVER

Loop and Temp Table usage in SQL SERVER 

Target :
To use Loop(may also use nested loop when needed) to fetch data then save into result table ,return result table

steps :
1.declare a result table

2.finish the data source query and save into #temptable

3.while(#temptable have data ) delete one row from #temptable

4.fetch data ,then fill in result table

sample codes :

BEGIN
DECLARE @FrmMstId UNIQUEIDENTIFIER
set @FrmMstId ='0E38D831-AC9D-4DEC-9422-11998A834269'

DECLARE  @FieldsDataTable TABLE
(
SetID int,
FieldName varchar(200),
Value varchar(max)
)

DECLARE @SetID AS int = 1
DECLARE @Item AS nvarchar(20)
DECLARE @Matter AS nvarchar(200)
DECLARE @CostClaimed AS float = 0
DECLARE @IsAgree AS int = 0
DECLARE @ProposedAmt AS float = 0
DECLARE @BocBreakdown AS nvarchar(200)
--fetch boc item
IF Object_id('tempdb..#T1') IS NOT NULL
DROP TABLE #T1

SELECT fbi.Id ,bi.Item,
bi.Matter ,fbi.CostClaimed,fbi.IsAgree,fbi.ProposedAmt
INTO #T1
FROM CM.FrmMst fm
JOIN HM.FrmBoc fb ON fm.Id = fb.FrmMstFK
JOIN HM.FrmBocItem fbi ON fbi.FrmBocFK = fb.Id
JOIN HM.BocItem bi ON bi.Id = fbi.BocItemFK
WHERE fm.Id = @FrmMstId AND
(bi.ExpiryDate > getdate() AND bi.effectiveDate <= getdate())
AND fb.DeletedBy IS NULL

ORDER BY CASE
WHEN IsNumeric(bi.Item) = 1 THEN Right('0000000000' + bi.Item + '0', 10)
ELSE Right('0000000000' + bi.Item, 10)
END

--process
DECLARE @FrmBocItemId AS UNIQUEIDENTIFIER

WHILE (SELECT Count(*) FROM #T1) > 0
BEGIN

SELECT TOP 1
@FrmBocItemId = Id,
@Item = Item,
@Matter = Matter,
@CostClaimed = CostClaimed,
@IsAgree = IsAgree,
@ProposedAmt = ProposedAmt
FROM #T1

INSERT INTO @FieldsDataTable values(@SetID, 'Item',ISNULL(@Item,''));
INSERT INTO @FieldsDataTable values(NULL, 'Matter',ISNULL(@Matter,''));
INSERT INTO @FieldsDataTable values(NULL, 'CostClaimed',@CostClaimed);
INSERT INTO @FieldsDataTable values(NULL, 'IsAgree',isNULL(@IsAgree,0));
INSERT INTO @FieldsDataTable values(NULL, 'Proposed Amount',isNULL(@ProposedAmt,0));

--process break down data

--step 1: check temp table is not exist
IF Object_id('tempdb..#T2') IS NOT NULL
DROP TABLE #T2

--step 2:fetch data into temp table
DECLARE @BreakdownId uniqueidentifier;
SELECT Id,BocItemBreakdownDesc INTO #T2 FROM HM.FrmBocItemBreakdown WHERE FrmBocItemFK = @FrmBocItemId;

--step 3:loop fetch data
WHILE (SELECT Count(*) FROM #T2) > 0
BEGIN
SELECT TOP 1 @BreakdownId = Id,@BocBreakdown = BocItemBreakdownDesc FROM #T2

INSERT INTO @FieldsDataTable values(NULL, '',ISNULL(@BocBreakdown,''));
DELETE #T2 WHERE Id = @BreakdownId
END

SET @SetID = @SetID + 1;

DELETE #T1 WHERE Id = @FrmBocItemId
END

END