Không độc đáo bảng/bí danh

Question

tôi nhận được lỗi ERROR 1066 (42000): Not unique table/alias:

tôi không thể tìm ra whats sai với nó.

SELECT Project_Assigned.ProjectID, Project_Title, Account.Account_ID, Username, Access_Type 
FROM Project_Assigned 
JOIN Account 
  ON Project_Assigned.AccountID = Account.Account_ID 
JOIN Project 
  ON Project_Assigned.ProjectID = Project.Project_ID 
where Access_Type = 'Client'; 

Answer 1

Hãy thử

SELECT pa.ProjectID, p.Project_Title, a.Account_ID, a.Username, a.Access_Type, c.First_Name, c.Last_Name 
     FROM Project_Assigned pa 
INNER JOIN Account a 
     ON pa.AccountID = a.Account_ID 
INNER JOIN Project p 
     ON pa.ProjectID = p.Project_ID 
INNER JOIN Clients c 
     ON a.Account_ID = c.Account_ID 
    WHERE a.Access_Type = 'Client'; 

Answer 2

select persons.personsid,name,info.id,address 
    -> from persons 
    -> inner join persons on info.infoid = info.info.id;