Answers for "show mysql error php"

install composer ubuntu

sudo apt update
sudo apt install php-cli unzip
cd ~
curl -sS https://getcomposer.org/installer -o composer-setup.php

HASH=`curl -sS https://composer.github.io/installer.sig`
echo $HASH
php -r "if (hash_file('SHA384', 'composer-setup.php') === '$HASH') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer
composer

apt search mbstring
sudo apt install php-mbstring

ubuntu install composer

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"

install composer ubuntu

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === '756890a4488ce9024fc62c56153228907f1545c228516cbf63f885e036d37e9a59d27d63f46af1d4d07ee0f76181c7d3') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
php composer-setup.php
php -r "unlink('composer-setup.php');"

composer install ubuntu

sudo mv composer.phar /usr/local/bin/composermixed

php show error

error_reporting(E_ALL);
ini_set('display_errors', 1);

php mysql error

mysqli_query($this->db_link, $query) or die(mysqli_error($this->db_link)); 
# mysqli_query($link,$query) returns 0 if there's an error.
# mysqli_error($link) returns a string with the last error message