Código SQL [-] SELECT nombre, codigo, ( (SELECT SUM(cantidad) FROM entradas WHERE documento = 'E' and cantidad > 0) - (SELECT SUM(cantidad) FROM entradas WHERE documento = 'S' and cantidad > 0) ) AS Resultado FROM entradas GROUP BY codigo
SELECT nombre, codigo, ( (SELECT SUM(cantidad) FROM entradas WHERE documento = 'E' and cantidad > 0) - (SELECT SUM(cantidad) FROM entradas WHERE documento = 'S' and cantidad > 0) ) AS Resultado FROM entradas GROUP BY codigo