Greenplum計算每月消耗的基本語法

SELECT
	dtime.sysmonth,
	opos.orderby_person,
CASE
		
		WHEN opos."消耗金額" IS NULL THEN
		0 ELSE opos."消耗金額" 
	END 
	FROM
		(
		SELECT
			DISTINCTto_char ( onday, 'yyyymm' ) sysmonthFROM (
			SELECT cast
				( '2015-01-01 00:00:00' AS TIMESTAMP ) + ( c || 'day' ) :: INTERVAL AS onday 
			FROM
				generate_series ( 0, 10300 ) AS tab ( c ) 
			) tb 
		WHERE
			onday <= CURRENT_DATEORDER BY TO_CHAR( onday, 'yyyymm' ) 
		) dtime
		LEFT OUTER JOIN ( SELECT * FROM dm.dm_operation_per_order_statistics ) opos ON opos.sh_month = dtime.sysmonth
ORDER BY
	dtime.sysmonth