Verwenden von PHP MYSQLi, um nur Debitoren und nur Kreditoren mit action_type DR und CR zu verwalten

Es scheint, dass Sie einfach Ihren HAVING ändern müssen -Klausel, um Fälle herauszufiltern, in denen balance ist entweder größer als Null (Schuldner) ODER balance kleiner als Null ist (Gläubiger).

Sie können auch bedingtes IF() verwenden Ausdrücke zur Bestimmung von dr/cr im balance Spalte.

Um Schuldner zu erhalten nur:

SELECT client_id, 
       Sum(Coalesce(CASE 
                      WHEN action_type = 'dr' THEN amount 
                    end, 0)) AS total_debits, 
       Sum(Coalesce(CASE 
                      WHEN action_type = 'cr' THEN amount 
                    end, 0)) AS total_credits, 
       Sum(Coalesce(CASE 
                      WHEN action_type = 'cr' THEN amount 
                    end, 0)) - Sum(Coalesce(CASE 
                                              WHEN action_type = 'dr' THEN 
                                              amount 
                                            end, 0)) AS total_debtors, 
       IF(Sum(Coalesce(CASE 
                         WHEN action_type = 'cr' THEN amount 
                       end, 0)) - Sum(Coalesce(CASE 
                                                 WHEN action_type = 'dr' THEN 
                                                 amount 
                                               end, 0)) > 0, 'dr', 'cr') AS balance 
FROM   tbl_balancesheet 
GROUP  BY client_id 
HAVING balance = 'dr' AND total_debtors <> 0

Um Gläubiger zu bekommen nur:

SELECT client_id, 
       Sum(Coalesce(CASE 
                      WHEN action_type = 'dr' THEN amount 
                    end, 0)) AS total_debits, 
       Sum(Coalesce(CASE 
                      WHEN action_type = 'cr' THEN amount 
                    end, 0)) AS total_credits, 
       Sum(Coalesce(CASE 
                      WHEN action_type = 'cr' THEN amount 
                    end, 0)) - Sum(Coalesce(CASE 
                                              WHEN action_type = 'dr' THEN 
                                              amount 
                                            end, 0)) AS total_debtors, 
       IF(Sum(Coalesce(CASE 
                         WHEN action_type = 'cr' THEN amount 
                       end, 0)) - Sum(Coalesce(CASE 
                                                 WHEN action_type = 'dr' THEN 
                                                 amount 
                                               end, 0)) > 0, 'dr', 'cr') AS balance 
FROM   tbl_balancesheet 
GROUP  BY client_id 
HAVING balance = 'cr' AND total_debtors <> 0