Cuota  DateCuota  DatePaid   Capital  Interest  Status
------  ----------  ----------  -------  -------  --------
     1  2018-05-07  2018-05-07  722.62   265.78         -1
     2  2018-06-06  2018-06-06  741.67   246.73         -1
     3  2018-07-06  2018-07-07  768.64   219.76         -1
     4  2018-08-05  2018-07-07  2305.92  400.00         -1
     5  2018-09-04  2018-07-07  5543.42  646.63         -1

SELECT IFNULL (SUM (Interest), 0) Interest FROM detailpre WHERE DateQuota <= '2018-06-30'

SELECT IFNULL (SUM (Interest), 0) Interest FROM detailpre WHERE DateQuota <= '2018-07-30'

SELECT IFNULL (SUM (Interest), 0) Interest FROM detailpre WHERE DateQuota <= '2018-08-30'