Trying to access a database in docker containers and php - php

Question

So I have the following docker-compose file and Dockerfile for php which I am using. These files are in a folder called cca4 and my php files are in a subdirectory of this called src. I am trying to access my mysql database that I am creating however I cannot select anything from it or insert anything. No matter what I do the queries will not work. Any idea on what is wrong? When I go into phpmyadmin I can see that my database is there however it is just not updating or being selected from. I am using nginx as the web server and php-fpm to communicate. I am doing this all from a Linux VM on GCP (Google Cloud Platform) so could be an issue with that maybe too. My php just cannot seem to pick up that there are any tables in the db or rows even after inserting them into phpmyadmin
version: '3.3'
services:
db:
image: mysql:latest
volumes:
- database:/var/lib/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: MyDBRoot123
MYSQL_DATABASE: assignment_four_data
MYSQL_USER: php
MYSQL_PASSWORD: php
container_name: db
networks:
- mynet
myphp:
build:
context: .
dockerfile: Dockerfile
depends_on:
- db
expose:
- 9000
restart: always
volumes:
- $PWD/src:/var/www/html
container_name: myphp
networks:
- mynet
mynginx:
depends_on:
- myphp
image: nginx:latest
ports:
- "8080:80"
restart: always
volumes:
- $PWD/src:/var/www/html
- $PWD/src/nginx.ini:/etc/nginx/conf.d/default.conf
container_name: mynginx
networks:
- mynet
phpMyAdmin:
depends_on:
- db
image: phpmyadmin:latest
restart: always
environment:
PMA_HOST: mysql
ports:
- "8082:80"
container_name: phpMyAdmin
networks:
- mynet
volumes:
database: {}
networks:
mynet:
driver: bridge
Here is the dockerfile.
FROM php:7.4-fpm
RUN pecl install igbinary \
&& pecl install redis \
&& docker-php-ext-install mysqli \
&& docker-php-ext-enable redis \
&& echo "extension=redis.so" > /usr/local/etc/php/conf.d/redis.ini
my php code.
<?php
$servername = "db";
$username = "php";
$password = "php";
$databse = "assignment_four_data";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $database);
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = 'SELECT * FROM Users';
$result = $mysqli_query($conn, $sql);
if (!$result) {
printf("false");
}
printf("Selected returned %d rows. \n", mysqli_num_rows($result));
?>
The error I keep receiving in my db.php file
Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, bool given in /var/www/html/db.php on line 18
Selected returned 0 rows
Is this a docker problem or a mysqli problem? My database is definitely there in phpmyadmin but I just can't get my db.php to communicate with it. Since the mysqli_query is returning false then my query obviously isn't able to work correctly with the mysql database. Even after creating tables and inserting values in phpmyadmin it still cannot detect anything.