2 个表查询的 LEFT JOIN 失败

Question

我正在尝试获取关于两个表的 2 个表的 left outer join，但我无法执行此查询，phpmyadmin 在运行宁此时给出 #1064 error on line 12查询：

SELECT 
pt.id as planid,
pt.trip_name,
pt.description,
cor.latitude,
cor.longitude,
bb.id as bookmarkid,
bb.num_of_persons as persons
FROM 
planned_trips as pt,
coordinates as cor,
LEFT JOIN Bookmarkedby as bb,Users as user
ON 
user.id = 1 AND
user.id = bb.user_id AND
bb.plannedtrips_id = pt.id AND
pt.coordinates_id = cor.id'

我挣扎了一个小时，我错过了什么？？我的数据库架构如下所示：

我目前正在准备我的查询，我需要运行在 codeIgnitor.

上进行此查询

Answer 1

每个table都需要一个单独的LEFT JOIN。

SELECT 
    pt.id as planid,
    pt.trip_name,
    pt.description,
    cor.latitude,
    cor.longitude,
    bb.id as bookmarkid,
    bb.num_of_persons as persons
FROM planned_trips as pt
INNER JOIN coordinates as cor ON pt.coordinates_id = cor.id
LEFT JOIN Bookmarkedby as bb ON bb.plannedtrips_id = pt.id
LEFT JOIN Users as user ON user.id = bb.user_id AND user.id = 1

Answer 2

问题出在行 LEFT JOIN Bookmarkedby as bb,Users as user 中。考虑将其更改为

FROM 
planned_trips as pt
JOIN coordinates as cor ON pt.coordinates_id = cor.id
LEFT JOIN Bookmarkedby as bb ON bb.plannedtrips_id = pt.id
LEFT JOIN Users as user ON user.id = bb.user_id 
AND user.id = 1

2 个表查询的 LEFT JOIN 失败

LEFT JOIN of 2 tables query is Failing

php

mysql

codeigniter

codeigniter-3