mysql - MySQL 查询连接表

Question

两个搜索都返回了正确的结果，但是当我尝试组合这两个查询时，它最终给出了错误的结果。

$query3 = "SELECT *
FROM airport_countries, airports
WHERE airports.iso_country=airport_countries.code &&
airport_countries.name like '%$search%'
ORDER BY pageviews DESC";

$query2 = "SELECT * 
    FROM airports 
    WHERE name like '%$search%' or 
municipality like '%$search%'
ORDER BY pageviews DESC";

VVVVVVVVV

SELECT *
FROM airport_countries, airports
WHERE airports.iso_country=airport_countries.code &&
airport_countries.name like '%$search%' or
    airports.name like '%$search%'  or 
airports. municipality like '%$search%'
ORDER BY pageviews DESC

我究竟做错了什么？

Answer 1

您的问题似乎是运算符优先级。为避免这种情况，只需使用大括号：

SELECT *
FROM airport_countries, airports
WHERE airports.iso_country=airport_countries.code
AND (
    airport_countries.name LIKE '%$search%'
    OR airports.name LIKE '%$search%'
    OR airports. municipality LIKE '%$search%'
    )
ORDER BY pageviews DESC

我还建议使用AND而不是&&（你正在写or而不是||- 看起来不太一致），但这只是我的意见，以提高可读性，不应该造成任何差异。