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当我在 MySQL 中运行查询时，我得到了预期的结果。该查询使用 MySQL 定义的变量按前 n 个分组。但是，在 PHP 中运行时，似乎“IF(@businessType=businessType...) 没有被正确评估并导致它选择所有结果。查询是：

SELECT RowNum,store_ID,businessType,createDate,expirationDate 
FROM (
    SELECT IF(@businessType = businessType, @ctr := @ctr + 1, @ctr := 1) as RowNum, 
    @businessType := businessType as businessType, store_ID, createDate, expirationDate 
    FROM stores
    JOIN (SELECT @ctr := 1) AS a 
    WHERE businessType IN (1,2,3) 
    AND ZIP = '11217' 
    AND state = 'NY' 
    ORDER BY businessType, createDate DESC) AS b 
WHERE RowNum in (1,2,3)

MySQL的结果是：

+--------+----------+--------------+---------------------+----------------+
| RowNum | store_ID | businessType | createDate          | expirationDate |
+--------+----------+--------------+---------------------+----------------+
|      1 |  4455977 |            1 | 2014-12-27 04:16:38 | 2014-12-31     |
|      2 |  4455977 |            1 | 2014-12-27 04:16:38 | 2014-12-31     |
|      3 |  1971257 |            1 | 2014-12-27 04:01:35 | 2014-12-31     |
|      1 |  3883533 |            2 | 2014-12-27 04:10:26 | 2015-01-01     |
|      2 |  3718085 |            2 | 2014-12-27 04:10:18 | 2015-01-01     |
|      3 |  3718085 |            2 | 2014-12-27 04:10:17 | 2015-01-01     |
|      1 |  2170979 |            3 | 2014-12-27 04:09:56 | 2015-01-10     |
|      2 |  2034241 |            3 | 2014-12-27 04:09:56 | 2015-01-10     |
|      3 |  2220899 |            3 | 2014-12-27 04:09:56 | 2015-01-10     |
+--------+----------+--------------+---------------------+----------------+

在 PHP 中，它返回 50 个结果，并且 RowNum 字段没有按预期递增。如何更正此查询以使其正确尊重“@”符号？注意：我在 PHP 中使用单引号，所以它不应该评估 '@' 符号。这是输出的一个片段：

Array
(
    [RowNum] => 1
    [businessType] => 1
    [createDate] => 2014-12-27 04:16:38
    [expirationDate] => 2014-12-31
)

Array
(
    [RowNum] => 1
    [businessType] => 1
    [createDate] => 2014-12-27 04:16:38
    [expirationDate] => 2014-12-31
)

Array
(
    [RowNum] => 1
    [businessType] => 1
    [createDate] => 2014-12-27 04:01:35
    [expirationDate] => 2014-12-31
)

Array
(
    [RowNum] => 1
    [businessType] => 1
    [createDate] => 2014-12-27 04:01:35
    [expirationDate] => 2014-12-31
)

Array
(
    [RowNum] => 1
    [businessType] => 1
    [createDate] => 2014-12-27 03:45:55
    [expirationDate] => 2014-12-29
)

...

Array
(
    [RowNum] => 1
    [businessType] => 3
    [createDate] => 2014-12-27 03:27:28
    [expirationDate] => 2014-12-29
)
4

1 回答 1

1

初始化@businessType变量

试试这个：

SELECT RowNum,store_ID,businessType,createDate,expirationDate 
FROM (SELECT IF(@businessType = @businessType:=businessType, @ctr := @ctr + 1, @ctr := 1) as RowNum, 
             businessType, store_ID, createDate, expirationDate 
      FROM stores, (SELECT @ctr := 1, @businessType := 0) AS a 
      WHERE businessType IN (1,2,3) AND ZIP = '11217' AND state = 'NY' 
      ORDER BY businessType, createDate DESC
    ) AS b 
WHERE RowNum in (1,2,3);
于 2014-12-27T09:29:50.997 回答