SQL Server 2017

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create table #Table1
( EmpID CHAR(4),
  Co_Code CHAR(2),
  Co_ShortName CHAR(3),
  Emp_Status CHAR(2)
 )
INSERT INTO #Table1
    ([EmpID], [Co_Code], [Co_ShortName], [Emp_Status])
VALUES
    ('WC11', '01', 'AA1', 'FT'),
    ('KC22', '02', 'BB1', 'PT'),
    ('MA33', '03', 'CC1', 'FT');

CREATE TABLE #Table2
    (EmpID CHAR(4), 
     Co_Code CHAR(2), 
     Co_ShortName CHAR(3), 
     Emp_Status CHAR(2));
    
INSERT INTO #Table2
    ([EmpID], [Co_Code], [Co_ShortName], [Emp_Status])
VALUES
    ('WC11', '04', 'DD1', 'FT'),
    ('KC22', '05', 'EE1', 'PT'),
    ('MA33', '06', 'FF1', 'FT');
    


   
    
6 rows affected

CREATE PROCEDURE #usp_Co_FT
(
  @i_c_EmpID CHAR(4)
)
AS
BEGIN
		SELECT 
		   T1.Co_Code ,T1.Co_Shortname
		FROM #Table1 AS T1 
		WHERE
			T1.EmpID = @i_c_EmpID
			AND T1.Emp_Status = 'FT'
END
CREATE PROCEDURE #usp_Co_PT
(
  @i_c_EmpID CHAR(4)
)
AS
BEGIN
		SELECT 
		   T2.Co_Code , T2.Co_Shortname
		FROM #Table2 AS T2
		WHERE
			T2.EmpID = @i_c_EmpID
			AND T2.Emp_Status ='PT'
END
DECLARE @c_EmpID CHAR(4) = '';
DECLARE @c_Emp_Status CHAR(2) = '';

SET @c_EmpID = 'WC11'
--SET @c_EmpID = 'KC22'

/*********vesrion 1******/

SELECT 
		CASE WHEN T1.Emp_Status = 'FT' THEN T1.Co_Code 
			 WHEN T1.Emp_Status = 'PT' THEN T2.Co_Code 
			 ELSE 'N/A' 
		END AS Co_Code,
		CASE WHEN T1.Emp_Status = 'FT' THEN T1.Co_Shortname 
			WHEN T1.Emp_Status = 'PT' THEN T2.Co_Shortname 
			ELSE 'N/A' 
		END AS Co_Shortname
	FROM #Table1 AS T1
		LEFT JOIN #Table2 AS T2
			ON T1.EmpID = T2.EmpID
			--AND T2.Emp_Status = 'PT'
	--WHERE T1.EmpID = @c_EmpID
	
	
/***********v2********/	
SELECT @c_Emp_Status =  T1.Emp_Status FROM #Table1 AS T1 WHERE T1.EmpID = @c_EmpID

IF @c_Emp_Status = 'FT'
BEGIN	
	EXEC  #usp_Co_FT @i_c_EmpID = @c_EmpID
END
ELSE IF @c_Emp_Status = 'PT'
	BEGIN
		EXEC  #usp_Co_PT @i_c_EmpID = @c_EmpID
	END
	

/*******version 3*****/
SELECT 
   T1.Co_Code ,T1.Co_Shortname
FROM #Table1 AS T1 
WHERE
    T1.EmpID = @c_EmpID
    AND T1.Emp_Status = 'FT'

UNION ALL  
    
SELECT 
   T2.Co_Code , T2.Co_Shortname
FROM #Table2 AS T2
WHERE
    T2.EmpID = @c_EmpID
    AND T2.Emp_Status ='PT'
  
    

	


Co_Code
Co_Shortname


01
AA1

05
EE1

03
CC1




Co_Code
Co_Shortname


01
AA1




Co_Code
Co_Shortname


01
AA1