sql Lite

Question

我正在尝试生成一个包含3列的报告，它们都来自同一个表，其中包含＆＃34;本地商店＆＃34;，＆＃34; ID＆＃34;，＆＃34; TotalSpend＆＃34;， ＆＃34;会员卡号＆＃34;。

Store       Totalnumofmembers    TotalSpendforall
-----      ------------------    ---------------
Store A       1500                   $100.50
Store B       2000                   $500.00
Store C       400                    $300.00

在尝试运行此查询时，它没有给我我想要的结果：

SELECT "Local Store",
    (SELECT count(ID) FROM ListMembers WHERE Id=a.Id and "Member Card Number" is not null) AS totalnumofmembers,
    (SELECT sum("total spend") FROM ListMembers WHERE Id=a.Id) AS totalspendforall FROM ListMembers a
GROUP BY "Local Store"

除了使用自联接之外还有其他方法吗？ 谢谢

Answer 1

如果您想在一个查询中执行此操作，则可以使用CASE语句对在同一查询中使用有效卡号的成员进行条件计数，以总计总支出。

SELECT `Local Store`,
    COUNT(CASE WHEN `Member Card Number` IS NOT NULL THEN 1 ELSE 0 END) AS totalnumofmembers,
    SUM(`total spend`) AS totalspendforall
FROM ListMembers
GROUP BY `Local Store`

如果您不介意使用子查询，那么您可以尝试以下

SELECT t1.`Local Store`, t1.totalnumofmembers, t2.totalspendforall
FROM
(
    SELECT `Local Store`, COUNT(*) AS totalnumofmembers
    FROM ListMembers
    WHERE `Member Card Number` IS NOT NULL
    GROUP BY `Local Store`
) t1
INNER JOIN
(
    SELECT `Local Store`, SUM(`total spend`) AS totalspendforall
    FROM ListMembers
    GROUP BY `Local Store`
) t2
    ON t1.`Local Store` = t2.`Local Store`

Answer 2

感谢名单。设法解决它。没有意识到SQL lite不像oracle那样使用to_date函数。都好。非常感谢你们。