Addition & Subtraction multiple column from multiple TABLES POSTGRES

Question

• table1(sum(col_claim)=100)

• table2(sum(col_claim)=50)

• table3(sum(col_release)=75)

• table4(sum(col_release_two)=25)

select total_claim-total_release;

Result = (100+50) - (75+25) = 50

Answer 1

Just inline the subqueries and do the arithmetic:

SELECT
    (SELECT SUM(col_claim) FROM table1) +
    (SELECT SUM(col_claim) FROM table2) -
    (SELECT SUM(col_release) FROM table3) -
    (SELECT SUM(col_release_two) FROM table4) AS result;