两个表的联接问题

Question

Hi I have two tables one is called project_table and another one called investment table.

project_table:

project_id               
project_name  
project_location         
project_phase        
project_capital      
project_total 
project_notes 
project_file 

investment table:

id  
project_id 
investor_id     
investment 

user table:

user_id
user_name
user_email
user_pass
user_role
user_phone 

I'm storing the investment from user in a table (investment) and linking that table to project table using project_id

What i need: Display Invested project data from a user. Means if a user login to admin they only need see they project which they have invested, Don't need to display all projects. A user may have option to invest in multiple projects. So basically if James login to admin he only need see project which have investment from James.

My function for this is:

public function list_all_projects_by_userid ($uid,$investor){

    $investors = DB::fetch('SELECT * FROM  project_table JOIN investment on project_table.project_id = investment.project_id;  ORDER BY project_id DESC');
   return $investors;   


        } 

Buts its not working, Please help me. i am using a Extended PDO class which have a fetch method.

Answer 1

Have a look at this!

SELECT * FROM  project_table t JOIN investment i on t.project_id = i.project_id where t.project_name='john' ORDER BY project_id DESC;

You placed a ";" before ORDER BY which is wrong. I guess that the above query would do the trick.

you have to pass the

project_name='john'

as per your requirement.

for that you need to make connection between usertable and project_table.

Answer 2

There is a syntax error in your query. Pl try this:

SELECT * FROM  project_table JOIN investment on project_table.project_id = investment.project_id  ORDER BY project_id DESC;

If your Join criteria is not meeting, pl explain your functionality in detail.

Answer 3

You need to put the ';' behind the whole query:

SELECT *
FROM  project_table JOIN investment
   on project_table.project_id = investment.project_id
ORDER BY project_id DESC;

Answer 4

since invester is an user so function doesn't need two arguments,so i kept it simple

public function list_all_projects_by_userid ($uid){
$sql="select * from investment_table Inner Join project_table
on project_table.project_id=investment_table.project_id
where investment_table='".$uid."' ORDER BY investment_table.project_id DESC";
$investors = DB::fetch($sql);
return $investors; 
}

Answer 5

In your function you put semi colon before the order by.

project_id present in both the tables. so you should mention in which table you need to set order by for project_id.

public function list_all_projects_by_userid ($uid,$investor){

$investors = DB::fetch('select * from investment_table, project_table where project_table.project_id=investment_table.project_id  ORDER BY investment_table.project_id DESC');

return $investors; }