Question

SET @qdate := '2014-02-17';
SELECT 
    com.trading_code,
    com.business_segment_id,
    dmkt.close_price,
    dmkt.cdate,
    dmkt.turnover,
    dmkt.volume,
    sh.total_no_share,
    IF(dmkt.close_price IS NULL,
        ((SELECT 
                close_price
            FROM
                daily_mkt_status
            WHERE
                trading_code = com.trading_code
                    AND cdate <= @qdate
            ORDER BY cdate DESC
            LIMIT 1) * sh.total_no_share),
        (dmkt.close_price * sh.total_no_share)) AS mcap
FROM
    company AS com
        LEFT JOIN
    daily_mkt_status AS dmkt ON (com.trading_code = dmkt.trading_code
        AND dmkt.cdate = @qdate )
        LEFT JOIN
    share_info AS sh ON (com.trading_code = sh.trading_code)

此代码仅在我使用像

这样的变量时才有效

SET @qdate :- '2014-02-17'

但我希望它是来自另一个表格的日期数组

SET @qdate IN (SELECT cdate FROM market_index);

qdate将在表market_index中循环显示所有日期。我已经完成了所有的数组变量问题，但由于我的代码的这一部分而没有为我工作

cdate <= @qdate

但我需要这部分在那里或我的查询不会给我我想要的输出。

希望我很清楚，并提前多多谢谢。

Answer 1

为什么不简单地加入market_index表？

SELECT
    com.trading_code,
    com.business_segment_id,
    dmkt.close_price,
    dmkt.cdate,
    dmkt.turnover,
    dmkt.volume,
    sh.total_no_share,
    mi.cdate
    IF(dmkt.close_price IS NULL,
        ((SELECT
                close_price
            FROM
                daily_mkt_status
            WHERE
                trading_code = com.trading_code
                    AND cdate <= mi.cdate
            ORDER BY cdate DESC
            LIMIT 1) * sh.total_no_share),
        (dmkt.close_price * sh.total_no_share)) AS mcap
FROM
    company AS com
    JOIN market_index AS mi
    LEFT JOIN daily_mkt_status AS dmkt ON (
        com.trading_code = dmkt.trading_code
        AND dmkt.cdate = mi.cdate
    )
    LEFT JOIN share_info AS sh ON (com.trading_code = sh.trading_code)

您可能还想添加GROUP BY子句，以便摆脱不必要的重复

查询中的日期数组

1 个答案: