Question

我有这样的SQL查询。当我通过我的php文件执行它时，它会给出超时错误。但是当运行相同的查询thoruhg php myadmin时，它会在几秒钟内给出结果。

SELECT
    cake_apartments.id,
    cake_apartments.Headline,
    cake_apartments.Description,
    cake_apartments.photoset_id,
    cake_apartments.Rental_Price,
    cake_apartments.Bedrooms,
    cake_apartments.Bathrooms
FROM
    cake_apartments,cake_neighborhoods
WHERE
    (cake_apartments.Rented = 0)
    AND
    (cake_apartments.status = 'Active')
ORDER BY
    cake_neighborhoods.Name DESC

我知道增加时间可以解决问题。但是我不希望这个查询花费超过30秒。

Answer 1

问题是你没有具体说明你们两个表之间的关系。它在phpmyadmin中快速返回，因为phpmyadmin添加了一个LIMIT子句，允许mysql服务器快速停止发送行，永远不会接近超时。

您认为查询只是检索公寓未租用且处于活动状态的行，但您真正得到的是行数*数据库中的邻域数。

像这样重写你的查询：

SELECT
    cake_apartments.id,
    cake_apartments.Headline,
    cake_apartments.Description,
    cake_apartments.photoset_id,
    cake_apartments.Rental_Price,
    cake_apartments.Bedrooms,
    cake_apartments.Bathrooms
FROM
    cake_apartments
JOIN
    cake_neighborhoods
  ON
    cake_neighborhoods.id = cake_apartments.neighborhood_id
WHERE
    (cake_apartments.Rented = 0)
    AND
    (cake_apartments.status = 'Active')
ORDER BY
    cake_neighborhoods.Name DESC

请注意，我只是猜到两个表在ON子句中是如何相关的，所以如果我弄错了你就必须调整它。

Answer 2

如果您只想要存在匹配的行，则SQL需要包含INNER JOIN。如果 cake_neighborhoods.cake_apartments_id 是 cake_neighborhoods 表中外键的名称，我建议您重写以下内容：

SELECT
    cake_apartments.id,
    cake_apartments.Headline,
    cake_apartments.Description,
    cake_apartments.photoset_id,
    cake_apartments.Rental_Price,
    cake_apartments.Bedrooms,
    cake_apartments.Bathrooms,
    cake_neighborhoods.Name
FROM
    cake_apartments,cake_neighborhoods
WHERE
    (cake_apartments.Rented = 0)
    AND
    (cake_apartments.status = 'Active')
    AND
    cake_neighborhoods.cake_apartments_id = cake_apartments.id
ORDER BY
    cake_neighborhoods.Name DESC

PHP MYSQL超时问题

2 个答案: