當我嘗試使用sql INNER JOIN查詢從3表獲取數據時出現錯誤

Question

在mysql數據庫中，我有3個表

1）tutor_signup_form，
2）tutor_signup_edu_psle和
3）tutor_signup_edu_olevel。

現在，我試圖從這3個表中獲取所有數據。 但是使用以下sql查詢無法正常工作。 我收到錯誤訊息

我正在使用的SQL查詢。

$query =  mysql_query("SELECT tutor_signup_form . *, tutor_signup_edu_psle . *, 
  tutor_signup_edu_olevel . * 
FROM tutor_signup_form
  INNER JOIN tutor_signup_edu_psle ON tutor_signup_form.tutor_id =  
  tutor_signup_form.tutor_id   ,    
  INNER JOIN tutor_signup_edu_olevel ON tutor_signup_form.tutor_id = 
  tutor_signup_edu_olevel.tutor_id
WHERE tutor_signup_form.tutor_id = '$tutor_id' ");

錯誤信息：

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in 
D:\software installed\xampp installed\htdocs\tutor\toplevel\edit_tutor.php on line 31

Answer 1

刪除INNER JOIN語句之間的逗號：

更改此：

INNER JOIN tutor_signup_edu_psle ON tutor_signup_form.tutor_id =  
tutor_signup_form.tutor_id  ,      
INNER JOIN tutor_signup_edu_olevel ON tutor_signup_form.tutor_id = 
tutor_signup_edu_olevel.tutor_id

對此：

INNER JOIN tutor_signup_edu_psle ON tutor_signup_form.tutor_id =  
tutor_signup_form.tutor_id
INNER JOIN tutor_signup_edu_olevel ON tutor_signup_form.tutor_id = 
tutor_signup_edu_olevel.tutor_id