update a column so duplicated values becomes unique - php

Question

Column title has a lot of duplicated values, more than once.
I need to update the column so, for example if 'gold' is duplicated - it becomes 'gold 1', 'gold 2', etc.
Something like this:
$st = $db->query("select id, title from arts order by title asc");
$st->execute();
$x = 0;
while($row = $st->fetch()){
$title = $row['title'];
//if($title.is duplicated){
$x++;
$title .= ' ' . $x;
$stb = $db->query("update arts set title = '" . $title . "' where id = " . $row['id']);
$stb->execute();
}
}
Any help?

Answer 1

It would be more efficient to do this in pure SQL rather than using PHP. Here is an approach that uses window functions, available in MySQL 8.0.
You can use a subquery to count how many title duplicates exists for each record, and assign a rank to each record within groups of records having the same title. Then, you can JOIN the subquery with the table to update. Where more than one record exists, you can append the row number to every record in the group.
Query:
UPDATE arts a
INNER JOIN (
SELECT
id,
title,
COUNT(*) OVER(PARTITION BY title) cnt,
ROW_NUMBER() OVER(PARTITION BY title ORDER BY id) rn
FROM arts
) b ON a.id = b.id
SET a.title = CONCAT(a.title, b.rn)
WHERE cnt > 1;
Demo on DB Fiddle
Sample data:
| id | title |
| --- | ------ |
| 10 | silver |
| 20 | gold |
| 30 | gold |
| 40 | bronze |
| 50 | gold |
| 60 | bronze |
Results after running the update query:
| id | title |
| --- | ------- |
| 10 | silver |
| 20 | gold1 |
| 30 | gold2 |
| 40 | bronze1 |
| 50 | gold3 |
| 60 | bronze2 |

Answer 2

Please see below code that working for me
// Create connection
$conn = new mysqli($servername, $username, $password,$dbname);
// get all row
$sql = "select id, title from arts order by title asc";
$result = $conn->query($sql);
while ($row=$result->fetch_assoc()) {
$title=$row['title'];
// select where title is same
$sql = "select * from arts where title='".$title."'";
$result2 = $conn->query($sql);
// if number of row is greater then one
if ($result2->num_rows > 1){
$x=0;
while ($row2=$result2->fetch_assoc()) {
$id=$row2['id'];
// skip first row
if($x>0){
$newTitle=$title.' '.$x;
$uquery = "update arts set title='".$newTitle."' where title='".$title."' and id=$id";
$update = $conn->query($uquery);
}
$x++;
}
}
}
and after query run

Answer 3

This works in MySql 5.7:
update arts a inner join (
select * from (
select t.id,
(
select count(*) + 1 from arts
where id < t.id and title = t.title
) counter
from arts t
) t
) t on t.id = a.id
set a.title = concat(a.title, ' ', t.counter)
where a.title in (
select h.title from (
select title from arts
group by title
having count(*) > 1
) h
);
See the demo.
For data:
| id | title |
| --- | -------- |
| 1 | silver |
| 2 | gold |
| 3 | diamond |
| 4 | bronze |
| 5 | gold |
| 6 | bronze |
| 7 | gold |
the result is
| id | title |
| --- | -------- |
| 1 | silver |
| 2 | gold 1 |
| 3 | diamond |
| 4 | bronze 1 |
| 5 | gold 2 |
| 6 | bronze 2 |
| 7 | gold 3 |

Answer 4

I think It would be more efficient to do this in SQL too, but you may can do a function to validate the duplicate, something like this:
function isDuplicated( $title, $db ){
$dp = $db->query("SELECT * FROM arts WHERE title = $title");
if ( $dp->num_rows > 1)
return true;
return false;
}
$st = $db->query("select id, title from arts order by title asc");
$st->execute();
$x = 0;
while($row = $st->fetch()){
$title = $row['title'];
if( isDuplicated( $title, $db ) ){
$x++;
$title .= ' ' . $x;
$stb = $db->query("update arts set title = '" . $title . "' where id = " . $row['id']);
$stb->execute();
}
}