Question

我是一个MySQL新手，无法弄清楚这里出了什么问题。我有两张桌子。左表称为锻炼。相关列为date（类型日期）和id（类型为int）。

右表名为Workout_locations（相关字段：workout_id type int, and location_id type int）。

加入字段为Workouts.id和Workout_locations.workout_id。

我想要做的就是获得两列的表格：date（来自锻炼）和location_id（来自Workout_locations）。我只需要根据几个字段从Workouts表中提取记录（sql语句应该明确这一点）。

这是我的sql语法：

SELECT Workouts.date as date, Workout_locations.location_id as loc_id
FROM Workouts 
WHERE Workouts.pacegroup_id='9' AND (Workouts.date BETWEEN '2013-08-19' AND '2013-08-25') 
INNER JOIN Workout_locations ON Workouts.id=Workout_locations.workout_id"

但是我收到了这个错误：

您的SQL语法有错误;检查手册对应于您的MySQL服务器版本，以便使用正确的语法靠近'INNER JOIN Workout_locations ON 第1行的Workouts.id = Workout_locations.workout_id'

我希望对于有这方面经验的人来说，这是一个非常容易发现的错误。谁能看到它？谢谢！

Answer 1

您的INNER JOIN应该出现在WHERE之前。我也不认为你需要parens around your BETWEEN clause，但我怀疑它会导致错误：

SELECT Workouts.date as date, Workout_locations.location_id as loc_id 
FROM Workouts 
INNER JOIN Workout_locations ON Workouts.id=Workout_locations.workout_id
WHERE Workouts.pacegroup_id = '9' 
AND Workouts.date BETWEEN '2013-08-19' AND '2013-08-25';

此外，虽然他们技术上让你逃脱它，但你应该避免使用＆＃34; date＆＃34;作为选定的列名称（它是reserved word）。

你也可以做一些精简，让事情更容易阅读：

SELECT Workouts.date AS wo_date, Workout_locations.location_id AS loc_id
FROM Workouts w
INNER JOIN Workout_locations l ON w.id = l.workout_id
WHERE w.pacegroup_id = '9'
AND w.date BETWEEN '2013-08-19' AND '2013-08-25';

MySQL内部连接查询语法错误

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