Database computing date, statistical system time (month) data

Database computing date, statistical system time (month) data calculated from the first day of the month to the last day of the date: www.2cto.com select date (rtrim (char (year (min (start_time )))) | '-' | rtrim (char (month (min (start_time) | '-1') as startTime, date (rtrim (char (year (max (start_time) | '-' | rtrim (char (month (max (start_time) + 1 month ))) | '-1') as endTime from table_A t; statistics for this month: select sum (MONTHLY_REPAYMENTS) as totle from TABLE_A where ID = '20160301' AND date ('2017-11-01 ') <date (current timestamp) and date ('2017-12-01')> date (current timestamp)