我是一名 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”。相关列是
date
(日期类型)和 id
(int 类型)。
右表称为
Workout_locations
(相关字段:workout_id type int, and location_id type int
)。
连接字段为
Workouts.id
和 Workout_locations.workout_id
。
我想做的就是获取一个包含两列的表格:
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 语句应该清楚地说明这一点)。
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"
但我收到此错误:
您的 SQL 语法有错误;检查手册 与您的 MySQL 服务器版本相对应,以便使用正确的语法 靠近“INNER JOIN Workout_locations ON” Workouts.id=Workout_locations.workout_id' 在第 1 行
我希望对于有这方面经验的人来说,这是一个很容易发现的错误。任何人都可以看到吗?谢谢!
您的
INNER JOIN
应位于 WHERE
之前。我也不认为你需要在 BETWEEN
子句周围使用括号,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,虽然它们
技术上让您侥幸逃脱,但您应该避免使用“日期”作为选定的列名称(这是一个保留字)。
您也可以进行一些简化,以使内容更易于阅读:
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';
SELECT Person.firstName, Person.lastName, IFNULL(Address.city, NULL) AS city, IFNULL(Address.state, NULL) AS state,
FROM Person
LEFT OUTER JOIN Address ON Person.personId = Address.personId;
这就是我得到的,请协助:MySQL 服务器版本,用于在“FROM Person”附近使用正确的语法 LEFT JOIN 地址 ON Person.personId = Address.personId' 在第 7 行