Mysql connection issue. If there is always connection issue. Try update mysql password with mysql_native_password keyword.
ALTER USER root@localhost identified with mysql_native_password by 'your_password';
‘Invalid default value’ = database install fail error
It is because php is too strict to allow the script to run.
vim /etc/my.cnf
Add below:
[mysqld] sql_mode=NO_ENGINE_SUBSTITUTION
Unable to install plugin. Add below into wp-config.php
define( 'FS_METHOD', 'direct' );
There might be plugin installation issue. So to me, just chmod 777 on wp-content folder:
chmod -R 777 wp-content
Other useful mysql command.
Completely delete wordpress tables
drop table wp_commentmeta, wp_options, wp_postmeta, wp_term_relationships, wp_term_taxonomy, wp_terms, wp_usermeta;
FLUSH PRIVILEGES;
GRANT ALL PRIVILEGES ON dbname.* TO 'username'@'localhost';
Script testing mysql connection
<?php
$mysqli = new mysqli('localhost', 'username', 'password', 'dbname');
/* check connection */
if ($mysqli->connect_errno) {
printf("Connect failed: %s\n", $mysqli->connect_error);
exit();
}
/* check if server is alive */
if ($mysqli->ping()) {
printf ("Our connection is ok!\n");
} else {
printf ("Error: %s\n", $mysqli->error);
}
/* close connection */
$mysqli->close();
?>