when i update my site from php 5.6 => 7.3.0 . i recviced this error 'Error establishing a database connection'..

But when i downgrade php to 5.6 , my website work fine . Anyone know this issue . this is my php 7.3.0 configure

'./configure' '--with-apxs2=/usr/bin/apxs' '--with-bz2' '--enable-calendar' '--with-curl' '--enable-exif' '--enable-ftp' '--with-gettext' '--with-pcre-dir' '--with-pdo-mysql=mysqlnd' '--with-mysqli=mysqlnd' '--enable-mysqlnd' '--with-pdo-sqlite'

when i update my site from php 5.6 => 7.3.0 . i recviced this error 'Error establishing a database connection'..

But when i downgrade php to 5.6 , my website work fine . Anyone know this issue . this is my php 7.3.0 configure

'./configure' '--with-apxs2=/usr/bin/apxs' '--with-bz2' '--enable-calendar' '--with-curl' '--enable-exif' '--enable-ftp' '--with-gettext' '--with-pcre-dir' '--with-pdo-mysql=mysqlnd' '--with-mysqli=mysqlnd' '--enable-mysqlnd' '--with-pdo-sqlite'

• php
• database

• Is it WordPress fault? Check which site you are on. – Max Yudin Commented Jan 23, 2020 at 20:48

1 Answer 1

Old versions of mysqlnd worked with legacy database passwords. I had to update the database to use more secure password format before the mysqlnd plugin would connect from Wordpress 5.0.3 to php 7.3

PHP Warning:  mysqli::__construct(): (HY000/2000): mysqlnd cannot 
connect to MySQL 4.1+ using the old insecure authentication. Please use an 
administration tool to reset your password with the command 
SET PASSWORD = PASSWORD('your_existing_password'). This will store a new, 
and more secure, hash value in mysql.user. If this user is used in other 
scripts executed by PHP 5.2 or earlier you might need to remove the old-
passwords flag from your my.cnf file in /root/db-test.php on line 2