[T-SQL] Dummy Column to match the UNION ALL operator

You must execute the code again to save those values in the database.

-- INIT database
CREATE TABLE SP_Main (
  SP_ID INT IDENTITY(1, 1),
  COLUMN1 DECIMAL,
  COLUMN2 DECIMAL,
  COLUMN3 DECIMAL,
  COLUMN4 DECIMAL

);

INSERT INTO SP_Main(COLUMN2, COLUMN3,COLUMN4) VALUES (1, 2, 3);
INSERT INTO SP_Main(COLUMN1, COLUMN2, COLUMN3,COLUMN4) VALUES (1, 2, 3, 4);
INSERT INTO SP_Main(COLUMN1, COLUMN2,COLUMN3) VALUES (2, 3, 4);
INSERT INTO SP_Main(COLUMN1, COLUMN2, COLUMN4) VALUES (3, 4, 1);

CREATE TABLE EM_Main (
  SP_ID INT IDENTITY(1, 1),
  COLUMN5 DECIMAL,
  COLUMN6 DECIMAL,
);

INSERT INTO EM_Main(COLUMN6) VALUES (1);
INSERT INTO EM_Main(COLUMN5) VALUES (2);
INSERT INTO EM_Main(COLUMN6) VALUES (3);

CREATE TABLE OP_Main (
  SP_ID INT IDENTITY(1, 1),
  COLUMN5 DECIMAL,
  COLUMN6 DECIMAL,
);

INSERT INTO OP_Main(COLUMN5) VALUES (3);
INSERT INTO OP_Main(COLUMN6) VALUES (2);
INSERT INTO OP_Main(COLUMN5) VALUES (1);

-- QUERY database
SELECT [EBDP], [PartialPrice] + [ActivityPrice] AS [TotalPrice], [ActivityPrice] 
FROM
(SELECT 
CONVERT(MONEY,COALESCE([COLUMN1], 0.00)) * CONVERT(MONEY,COALESCE([COLUMN2],[COLUMN3], 1.00)) AS [EBDP],
CONVERT(MONEY,COALESCE([COLUMN4], 0.00)) AS [ActivityPrice],
CONVERT(MONEY,COALESCE([COLUMN1], 0.00)) * CONVERT(MONEY,COALESCE([COLUMN2],[COLUMN3], 1.00))  AS [PartialPrice]

from [SP_Main] e) as TABLE1

UNION ALL

select 
    CONVERT(MONEY,0.00) AS [EBDP],
    CONVERT(MONEY,COALESCE([COLUMN5], 0.00)) AS [TotalPrice],
    CONVERT(MONEY,COALESCE([COLUMN6], 0.00)) AS [ActivityPrice]

from EM_Main

UNION ALL

SELECT 
    CONVERT(MONEY,0.00) AS [EBDP],
    CONVERT(MONEY,COALESCE([COLUMN5], 0.00)) AS [TotalPrice],
    CONVERT(MONEY,COALESCE([COLUMN6], 0.00)) AS [ActivityPrice]

FROM OP_Main

EBDP	TotalPrice	ActivityPrice
.0000	3.0000	3.0000
2.0000	6.0000	4.0000
6.0000	6.0000	.0000
12.0000	13.0000	1.0000
.0000	.0000	1.0000
.0000	2.0000	.0000
.0000	.0000	3.0000
.0000	3.0000	.0000
.0000	.0000	2.0000
.0000	1.0000	.0000

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(10 rows affected)