Display all employee i want to display all employee from tbl_Employee_Master ,weather emp_Id is exit or not in  #tbl_assign_Allowance_Deduction table
I developed a query,but it fetching those record where asd.sal_ID is null,but i want to fetch all employee from tbl_Employee_Master table,when ever this query is run'
Create Table #tbl_Designation (Designation_ID int, Designation_Name varchar(50));
CREATE TABLE #tbl_Employee_Master (emp_ID INT,emp_Name Varchar(50),emp_salary int,Designation_ID 

    int,emp_OT int );  
CREATE TABLE #tbl_Type_allowance_Deduction (DA_ID INT,DA_Name Varchar(50), DA_TYPE_ID Varchar(50));  
CREATE TABLE #tbl_assign_Allowance_Deduction (assign_ID INT,EMP_ID int ,DA_ID int, Assign_amt int,Sal_ID int);

Insert into #tbl_Designation values  
(1,'officer'),  
(2,'Executive')  
  
Insert into #tbl_Employee_Master values  
(1001,'Irfan',10000,1,20),  
(1002,'Khan',10500,2,20),  
(1003,'Akhter',1200,1,20) , 
(1004,'Ali',8000,2,20),  
(1005,'Jhain',3300,1,20) 
  
insert into #tbl_Type_allowance_Deduction values  
(1,'Loan','Deduction'),  
(2,'Medical','Allowance'),  
(3,'Rent','Allowance'),  
(4,'Conveyance','Allowance'),  
(5,'Advance','Deduction'),  
(6,'Mobile','Allowance')  
  
insert into #tbl_assign_Allowance_Deduction values  
(111,1001,1,500,111),  
(112,1001,2,500,111),  
(113,1002,3,540,111),  
(114,1003,4,200,null),  
(115,1003,6,400,null)  

 SELECT  (M.Emp_ID) , M.EMp_Name , M.EMP_Salary ,D.Designation_Name as Designation,
       SUM(CASE T.DA_Name  WHEN 'Loan' THEN (ASD.assign_amt)ELSE 0 END) Loan, 
        SUM(CASE T.DA_Name  WHEN 'Advance' THEN (ASD.assign_amt)ELSE 0 END) Advance,
           SUM(CASE T.DA_Name  WHEN 'Mobile' THEN (ASD.assign_amt)ELSE 0 END) Mobile,
               SUM(CASE T.DA_Name  WHEN 'Conveyance' THEN (ASD.assign_amt)ELSE 0 END) Conveyance,
               SUM(CASE T.DA_Name  WHEN 'Medical' THEN (ASD.assign_amt)ELSE 0 END) Medical,
                  SUM(CASE T.DA_Name  WHEN 'Rent' THEN (ASD.assign_amt)ELSE 0 END) House_Rent,
isnull(M.emp_OT,0) as emp_OT
,0 'txtpresent', 0 'txtabsent',0 'txtsalary',0 'lbOT_Amount',0'txthour',asd.Sal_ID
FROM #tbl_Employee_Master M
 inner join #tbl_designation D on D.Designation_ID=M.Designation_ID
   left   join #tbl_assign_Allowance_Deduction ASD on asd.Emp_ID=M.Emp_ID
   left outer join #tbl_Type_allowance_Deduction T on T.DA_ID=ASD.DA_ID
where asd.sal_ID is null
 group by M.Emp_ID,M.EMp_Name,M.EMP_Salary,D.Designation_Name,M.emp_OT,asd.Sal_ID
I developed a query,but it fetching those record where asd.sal_ID is
null,but i want to fetch all employee from tbl_Employee_Master
table,when ever this query is run'

The asd.sal_ID IS NULL criteria in the WHERE clause will exclude all employees with non-null deductions. Move that criteria the the ON clause of the allowance deduction LEFT JOIN to include allowance deduction rows with NULL Sal_ID values without excluding employees with non-null values too:
SELECT
      M.Emp_ID
    , M.EMp_Name 
    , M.EMP_Salary 
    , D.Designation_Name AS Designation
    , SUM(CASE T.DA_Name  WHEN 'Loan' THEN (ASD.assign_amt) ELSE 0 END) Loan
    , SUM(CASE T.DA_Name  WHEN 'Advance' THEN (ASD.assign_amt) ELSE 0 END) Advance
    , SUM(CASE T.DA_Name  WHEN 'Mobile' THEN (ASD.assign_amt) ELSE 0 END) Mobile
    , SUM(CASE T.DA_Name  WHEN 'Conveyance' THEN (ASD.assign_amt) ELSE 0 END) Conveyance
    , SUM(CASE T.DA_Name  WHEN 'Medical' THEN (ASD.assign_amt) ELSE 0 END) Medical
    , SUM(CASE T.DA_Name  WHEN 'Rent' THEN (ASD.assign_amt) ELSE 0 END) House_Rent
    , ISNULL(M.emp_OT,0) AS emp_OT
    , 0 AS 'txtpresent'
    , 0 AS 'txtabsent'
    , 0 AS 'txtsalary'
    , 0 AS 'lbOT_Amount'
    , 0 AS 'txthour'
    , ASD.Sal_ID
FROM #tbl_Employee_Master M
INNER JOIN #tbl_designation D ON D.Designation_ID=M.Designation_ID
LEFT JOIN #tbl_assign_Allowance_Deduction ASD ON asd.Emp_ID=M.Emp_ID AND ASD.sal_ID IS NULL
LEFT JOIN #tbl_Type_allowance_Deduction T ON T.DA_ID=ASD.DA_ID
GROUP BY
      M.Emp_ID
    , M.EMp_Name
    , M.EMP_Salary
    , D.Designation_Name
    , M.emp_OT
    , ASD.Sal_ID;