mysql PHP join - syntax issue

Question

I am trying to join 3 tables but I keep getting an error with my query. I am not sure what I am doing wrong. I must be doing something incorrect with my syntax but I am not quite sure what is wrong.

SELECT project_timecard_tasks.DateTime,
        project_timecard_tasks.Total_Hours,
        project_timecard_tasks.User_ID,
        project_timecard_tasks.Task_ID,
        project_timecard_tasks.Project_ID,
        users.User_ID,
        users.FirstName,
        users.LastName,
        tasks.id,
        tasks.taskName

 FROM project_timecard_tasks

 JOIN project_timecard_tasks ON project_timecard_tasks.User_ID = users.User_ID 
 AND project_timecard_tasks.Task_ID = tasks.id

 WHERE project_timecard_tasks.Project_ID = '$jobNumber'

Answer 1

Your JOIN statement is a little wonky. Try this:

SELECT project_timecard_tasks.DateTime,
        project_timecard_tasks.Total_Hours,
        project_timecard_tasks.User_ID,
        project_timecard_tasks.Task_ID,
        project_timecard_tasks.Project_ID,
        users.User_ID,
        users.FirstName,
        users.LastName,
        tasks.id,
        tasks.taskName

 FROM project_timecard_tasks

 JOIN users ON project_timecard_tasks.User_ID = users.User_ID 
 JOIN tasks ON project_timecard_tasks.Task_ID = tasks.id

 WHERE project_timecard_tasks.Project_ID = '$jobNumber'

Answer 2

You are selecting data from three tables (project_timecard_tasks , users and tasks) but in from clause you are mentioning only 1 table. you need to mention all tables names like:

 FROM project_timecard_tasks ,users, tasks

Answer 3

You JOIN is incorrect. You need to specify the tables you are joining. Replace it with:

JOIN users ON project_timecard_tasks.User_ID = users.User_ID 
JOIN tasks ON project_timecard_tasks.Task_ID = tasks.id

Answer 4

删除AND并在第二个连接语句中使用JOIN 。

JOIN project_timecard_tasks ON project_timecard_tasks.User_ID = users.User_ID JOIN project_timecard_tasks.Task_ID = tasks.id