php - 通过联接从多个表中选择列

我有两个桌子：

users (username, business_id, etc.)

businesses (business_id, service_type, latitude, longitude, etc.)

我有以下查询，可以正常工作：

SELECT username, users.business_id FROM users JOIN businesses
ON users.business_id = businesses.business_id WHERE service_type = ?

现在，我想在结果中也有“企业”表中的“纬度”和“经度”列。我怎样才能做到这一点？

我尝试执行以下操作，但出现错误：

SELECT username, users.business_id, businesses.latitude, businesses.longitude
FROM users, businesses JOIN businesses
ON users.business_id = businesses.business_id WHERE service_type = ?

什么是获得所需结果的正确方法？

最佳答案

使用显式联接语法：

SELECT username, users.business_id,
       businesses.latitude, businesses.longitude
FROM users
JOIN businesses
   ON users.business_id = businesses.business_id
WHERE service_type = ?

您正在将隐式与显式语法混合在一起。因此，实际上没有必要在, businesses子句中使用FROM。