I have the following query in MSSQL:
select TRANSACTION_TYPE_ID ,COUNT(TRANSACTION_TYPE_ID)AS NUMBER_OF_TRANSACTIONS ,CAST(SUM(AMOUNT)AS DECIMAL (30,2)) AS TOTA
SELECT FROM_UNIXTIME( ( ROUND((UNIX_TIMESTAMP( floor(timestamp_column)) / 60 ),0) * 60 ) ) rounded_time FROM mysql_table WHERE timestamp_column BETWEEN STR_TO_DATE('31/07/2012','%d/%m/%Y') AND STR_TO_DATE('01/08/2012','%d/%m/%Y')