Php - MySql 不从表中获取数据

Question

I have a simple php sql script to display datas in datatable.
It displays the details of the children from tbl_child and fetch the latest course from the table_class and both the table are connected to l.childfkey=c.childpid.

here is the problem. the following script work well if i place

$select = $pdo->prepare(" select * from tbl_child c .......................... )

but i dont need all the fields so if i mention only some fields it wont show the records from tbl_class.

Here is the script which is not fetching from tbl_class

$select = $pdo->prepare(" select 
                   childpid,
                   child_name,
                   child_surname,
                   child_birth,
                   child_age,
                                        
                   from tbl_child c 
                   
                   LEFT JOIN (SELECT classpid,childfkey,class_courseyear,class_course FROM tbl_class  where classpid IN (
                   
                    SELECT MAX(classpid)
                    FROM tbl_class 
                    GROUP BY childfkey
                   
                   
                   ))l ON l.childfkey=c.childpid

thanks in advance.

Answer 1

I noticed you use an alias in your child table tbl_child c but in the above, you select your column without the alias c .

Select column with the alias like:-

c.childpid, c.child_name

Thanks