Creating a column number with the number in the column - php

Question

id | ozID | ozDa1 | ozDa2 | ozDa3
-----------------------------------------------
1 | 3,4 | Khar | Lorem | Emre
2 | 1,2 | Imson | Berkay | ade
3 | 2 | abc | Goksel | casc
4 | 5 | teq | Insanlik | fdsc
5 | 1,5,2 | asd | Oyle | asdas
6 | 2,1 | fav | Boyle | dsssa
7 | 3 | qwrewq | Filan | dcsd
I can write the content like:
$partNameWD->ozDa2; // Berkay
But the number at the end can be variable, like this: ozDa4.
At first I get the data from the ozID table, for example: 1,2
What does it mean 1,2?
It points to column numbers: ozDa1 and ozDa2
Access to this number is like this:
$ozColNo = explode(",", $partNameWD->ozID);
foreach (ozColNo as $ozColId) {
echo ozColId." - "; // 1 - 2
}
So what is my problem?
How do I get data from the column with these numbers? So, how can I print the data from one and the second
It has to be transformed: ozDa1 // Imson and ozDa2 // Berkay
Please can you tell me the method?
Thanks

Answer 1

I'm not 100% sure that I correctly understand the question, but you can get the mapping between "column number" and "column name" in information_schema.columns. So, if you are given a number, you can look up the name using:
select column_name
from information_schema.columns
where table_name = #table_name and table_schema = #table_schema and
ordinal_position = #op;
You can do a group of columns with a slightly more complicated approach (because I assume ordering is important)
select group_concat(c.column_name order by cols.ordering) as columns
from (select 1 as colpos, 1 as ordering union all
select 2, 2
) cols join
information_schema.columns c
on c.ordinal_position = cols.colpos
where table_name = #table_name and table_schema = #table_schema;

Answer 2

Try this.
$output= $partNameWD->{'ozDa' . $ozColId};
echo $output;
Check out the PHP.net site for this
http://php.net/manual/en/language.variables.variable.php
Caution
Further dereferencing a variable property that is an array has
different semantics between PHP 5 and PHP 7. The PHP 7.0 migration
guide includes further details on the types of expressions that have
changed, and how to place curly braces to avoid ambiguity.