Dynamic SQL query in SQL Server 2008 stored procedure - sql-server

Question

I have 4 tables A, B, C and X.
X table :
Icid Trade_Id Counter_Party
---------------------------------
1 101 HDFC1
2 102 HDFC1
3 103 HDFC2
4 104 HDFC2
5 105 HDFC2
6 106 HDFC3
7 107 HDFC4
8 108 HDFC4
9 109 HDFC5
10 110 HDFC5
A table :
Icid Trade_Id Name
----------------------------------
1 110 HDFC Bank Pvt Ltd
2 105 HDFC Bank Pvt Ltd
3 101 HDFC Bank Pvt Ltd
4 102 HDFC Bank Pvt Ltd
B table:
Icid Trade_Id Name
----------------------------------------
1 103 HSBC Pvt Ltd
2 104 HSBC Pvt Ltd
3 106 HSBC Pvt Ltd
C table :
Icid Trade_Id Name
--------------------------------------
1 107 HK Pvt Ltd
2 108 HK Pvt Ltd
3 109 HK Pvt Ltd
A, B, C table like this and I have created another table and store tables name as below.
Findtbl table:
Icid Table_name
------------------
2 A
3 B
4 C
I need to table X Trade_ID find to tables A, B and C. If found in table A, then print location column INDIA, if found in table B then print location column USA, and if found in table C, then location column is Hongkong in #Temp table location, Trade_Id, Name columns:
#temp table :
Icid location Trade_Id Name
I tried this:
Declare #Fst_value nvarchar(100)
Declare #Counter INT
Declare #tablename nvarchar(20)
Declare #sql nvarchar(max)
Declare #isvalue int
Declare #loop int = 1
Declare #sqlsecond nvarchar(max)
Declare #sqlthird nvarchar(max)
SET #Fst_value = '104'
SET #Counter = (Select COUNT(Icid) From Findtbl)
WHILE #Loop < = #Counter
BEGIN
SET #tablename = (SELECT Table_name
FROM Findtbl
WHERE Icid = #Loop)
SET #sql = 'Select #isvalue = Icid,#sqlsecond = Trade_Id,#sqlthird = Name From '+#tablename+' Where Trade_Id = '+#Fst_value+''
Execute sp_executesql #sql,N'#isvalue int OUTPUT,#sqlsecond nvarchar OUTPUT,#sqlthird nvarchar OUTPUT',#isvalue = #isvalue OUT,#sqlsecond = #sqlsecond OUT,#sqlthird = #sqlthird OUT
if(#isvalue <> 0)
begin
Select #sql
break
end
SET #isvalue = 0
SET #Loop = #Loop + 1
END
This code is contained in a stored procedure.

Answer 1

I'll give it a shot, though you probably need to spend some time re-stating your question.
I'm going to have to ignore the procedural code, and use set-based code.
insert into #temp (Icid, location, Trade_Id, Name)
select case
when A.Trade_ID is not null then A.Icid
when B.Trade_ID is not null then B.Icid
when C.Trade_ID is not null then C.Icid
end
,case
when A.Trade_ID is not null then 'INDIA'
when B.Trade_ID is not null then 'USA'
when C.Trade_ID is not null then 'Hongkong'
end
,case
when A.Trade_ID is not null then A.Trade_ID
when B.Trade_ID is not null then B.Trade_ID
when C.Trade_ID is not null then C.Trade_ID
end
,case
when A.Trade_ID is not null then A.Name
when B.Trade_ID is not null then B.Name
when C.Trade_ID is not null then C.Name
end
from X
left outer join A on X.Trade_ID on A.Trade_ID
left outer join B on X.Trade_ID on B.Trade_ID
left outer join C on X.Trade_ID on C.Trade_ID