Using a Variable as a List of Fields

Question

MySQL

I want to link 2 tables:

SELECT T1.id, <b>???</b>
FROM sc_user T1 
INNER JOIN sc_user_value T2 ON T1.id_user = T2.id
WHERE T1.ID = 1
LIMIT 1;

The required fields of the second table are stored in the third table, I get the query:

SELECT GROUP_CONCAT(CONCAT('T2.', name) SEPARATOR '+" "+') AS name FROM sc_user_field WHERE use_as_name ORDER BY sort

Query result: T2.last_name+" "+T2.first_name+" "+T2.second_name

Question: how to combine two queries into one?

Answer 1

No need to store a list of field names in another table.
It is necessary to read at least a primer on relational databases and learn how to use them humanly.

Answer 2

Never shift business logic to the database. A database is a place where data is stored, not processed. Then your applications will be dependent.

Answer 3

You thrust the 2nd request in under request of the first.
Get something like this.

Select t1.*,t2.*,t3.*
from t1
inner join t2 on t2.id=t1.t2id
inner join (select * from t3 ) as t3 on t3.id=t2.t3id

Answer 4

Throw off the structure of the tables, you will get an answer faster.

Answer 5

simplified model:
sc_user
id -> INT
sc_user_value
id -> INT
id_user -> INT (associated with sc_user.id)
user-added fields
sc_user_fields
name - CHAR (stores field name sc_user_value. user-added fields )

Answer 6

simplified model:
sc_user
id -> INT
sc_user_value
id -> INT
id_user -> INT (associated with sc_user.id)
user-added fields
sc_user_fields
name - CHAR (stores field name sc_user_value.user-added fields)

Answer 7

using php, of course, you can split the request into 2 requests, in the first - get the value, and insert it into the second request ...
but ... is there a way to do it in one request!