How to fetch results in while loop - php

Question

I have the following 2 tables.
| ID | Name | Category |
|----|-------------|----------|
| 1 | Foo bar | 3 |
| 2 | Bar foo | 2 |
| 3 | Baz Foo | 3 |
| 4 | Baz Foo2 | 1 |
| 5 | Baz Foo3 | 1 |
| 3 | Baz Foo | 1 |
| ID | Category_name |
|----|---------------|
| 1 | Cat 111 |
| 2 | Cat 222 |
| 3 | Cat 3333 |
I want to display all categories with counter, example:
Cat111 - 3
Cat222 - 2
Cat333 - 2
I tried to do it by the following way, but its not working:
$query = mysqli_query('SELECT * FROM gallery');
while($row = mysqli_fetch_assoc($query)) {
$query_cat = mysqli_query($conn, "SELECT * FROM `pics_cat` WHERE id = '".$row['category']."' GROUP BY category_name");
$rowCat = mysqli_fetch_assoc($query_cat);
echo $rowCat['category_name'];
echo $rowCat['cnt'];
}

Answer 1

You are not sharing the names of the tables, but I assume the first one is Gallery and the second one is pics_cat
If your tables are not going to be very large, I suggest you to solve everything with a single join query, which simplifies the logic of your script.
$query = mysqli_query($conn, 'SELECT p.Category_name,COUNT(g.ID) AS cnt FROM `gallery` AS g LEFT JOIN `pics_cat` AS p ON p.ID = g.Category GROUP BY p.ID');
while($row = mysqli_fetch_assoc($query)) {
echo $rowCat['Category_name'];
echo $rowCat['cnt'];
}
If you prefer to do this with 2 queries in a loop, it's much easier to start from the Category table and then move to the gallery
$query = mysqli_query($conn, 'SELECT * FROM `pics_cat` ORDER BY ID');
while($row = mysqli_fetch_assoc($query)) {
$query_count = mysqli_query('SELECT COUNT(ID) AS cnt FROM `gallery` WHERE Category = '.$row['ID'].'');
$row_count = mysqli_fetch_assoc($query_count);
echo $row['Category_name'];
echo $row_count['cnt'];
}