Question

我正在开发一个PHP接口来显示来自两个不同数据库的一些结果：一个MySQL（.sql）和一个Access（.mdb）。当我查询结果时，我让用户选择他想要列出的数量，这样我就可以通过一些PHP乐趣来限制和分页。
这对于MySQL DB来说是完美无缺的，其中 LIMIT 子句以一种简洁的方式完成所有事情。 Access DB是一个不同的说法：Access没有LIMIT子句，所以我要使用 TOP 子句。太糟糕了，这个让后面的分页变得痛苦我在this question的接受答案中找到了一个很好的例子，但我遇到了问题。首先，让我向您展示几个片段查询：

QUERY＃1

SELECT TOP 5 *                 
FROM `Table_1` INNER JOIN `Table_2`
ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID`
AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp`
WHERE `Table_1`.`Some_ID` LIKE 'ID %' AND `Table_1`.`Timestamp` LIKE '2018/03/20 %';

QUERY＃2

SELECT TOP 5 *                 
FROM `Table_1` INNER JOIN `Table_2`
ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID`
AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp`
WHERE `Table_1`.`Some_ID` LIKE 'ID %' AND `Table_1`.`Timestamp` LIKE '2018/03/20 %'
ORDER BY `Table_1`.`Some_ID`;

查询＃1 按要求向我显示前5个结果太糟糕了，当我添加 ORDER BY 子句时，查询＃2 会让我回复满足条件的所有结果。

对于像这样的MySQL查询，同样的事情不会发生：

QUERY＃3

SELECT * 
FROM `Table_1` INNER JOIN `Table_2`
ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID` 
AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp` 
WHERE `Table_1`.`Some_ID` LIKE 'ID %' AND `Table_1`.`Timestamp` LIKE '2018/03/20 %'
ORDER BY `Table_1`.`Some_ID`
LIMIT 0, 5;

那么，我是否在使用Access查询时出错？要完成我的问题，这是我的最终Access查询应该是这样的（我稍微修改了上述主题中提出的那个）：

QUERY＃4

SELECT * 
FROM `Table_1` INNER JOIN `Table_2` 
ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID` 
AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp` 
WHERE EXISTS (
    SELECT TOP 5 * FROM (
        SELECT TOP 10 * 
        FROM `Table_1` INNER JOIN `Table_2` 
        ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID` 
        AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp` 
        WHERE `Table_1`.`Some_ID` LIKE 'ID %' AND `Table_1`.`Timestamp` LIKE '2018/03/20 %') 
    ORDER BY `Table_1`.`Some_ID` DESC) 
ORDER BY `Table_1`.`Some_ID` ASC;

Answer 1

最后我设法解决了我的问题。我会发布我的查询以防其他人遇到同样的问题。

SELECT TOP 5 *
FROM `Table_1` INNER JOIN `Table_2`
ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID`
AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp`
WHERE `Table_1`.`Timestamp`
IN (
    SELECT TOP 5 `Table_1`.`Timestamp`
    FROM (
        SELECT TOP 10 *
        FROM `Table_1` INNER JOIN `Table_2`
        ON `Table_1`.`Some_ID` = `Table_2`.`Some_ID`
        AND `Table_1`.`Timestamp` = `Table_2`.`Timestamp`
        WHERE `Table_1`.`Some_ID` LIKE 'ID %'
        AND `Table_2`.`Timestamp` LIKE '2018/03/20 %'
        ORDER BY `Table_1`.`Timestamp` ASC)
    ORDER BY `Table_1`.`Timestamp` DESC)
ORDER BY `Table_1`.`Timestamp` ASC;

只需使用“ASC”和“DESC”即可获得您愿意回复的结果。

Access DB：TOP子句和嵌套查询+ PHP分页

1 个答案: