如何在postgreSQL中获取最后24小时的数据

我想获得最后24小时的数据.我在postgresql中写了一个查询,如下所示.但我无法按照我的预期得到答案.

SELECT startdate::timestamp AS startdate,(DATE_PART('hour',startdate::timestamp)::integer) as hrs,count(guorderid)
    FROM ord_entitlement
    WHERE DATE_PART('Day',CURRENT_DATE::timestamp - startdate::timestamp) < 1
    AND DATE_PART('hour',startdate::timestamp) <= 24
    GROUP BY  hrs,startdate
    ORDER BY startdate

如果您使用CURRENT_DATE,则不会使用Now()函数.试试以下,

SELECT startdate::timestamp AS startdate,count(guorderid)
        FROM ord_entitlement
        WHERE DATE_PART('Day',Now() - startdate::timestamptz) < 1
        GROUP BY  hrs,startdate
        ORDER BY startdate