僅更改BIGINT類型的日期時間戳記的時間

Question

我想在stock_date中將時間設置爲00:00:00而不更改年份，月份或日期，即如果日期表示形式爲07-07-1994 10:45:23，我希望將其改爲07-07-1994 00:00:00我環顧四周，但沒有找到任何可能有所幫助的東西。以下是我的查詢。謝謝。

SELECT stock_date   AS longDate, 
     'Tagged containers' AS transactionType, 
     tagged_cnt   AS quantity 
FROM RFID_INVENTORY_DAILY_STOCK 
WHERE grp_org_id = (SELECT GRP_ORG_ID 
        FROM GROUP_ORG_MAPPING 
        WHERE 
        grp_id =#group_id# 
        AND org_type = 'S' AND isactive=1 
        LIMIT 1) 
    AND stock_date >= #fromDate# 
    AND stock_date <= #toDate# 

Answer 1

使用date_trunc這樣的：

SELECT date_trunc('day', current_timestamp); 

     date_trunc  
------------------------ 
2017-10-06 00:00:00+02 
(1 row)