Сума на подзаявки на SQL Server

Опитайте това:

SELECT ID, col1, col2, [Total] = (col1 + col2)
FROM (
    SELECT Id,
    (SELECT COUNT(*) FROM table1 LEFT JOIN table2 on ...) as col1,
    (SELECT COUNT(*) FROM table3 LEFT JOIN table4 on ...) as col2
    FROM [TABLE]) T

Надявам се, че това помага.