DbSchema for MariaDB Databases

DbSchema is a powerful database management and design tool for MariaDB. It offers features such as visual schema design, team collaboration with GIT, schema deployment and HTML schema documentation.

How to Connect to MariaDB Database

1. Access the Connection Dialog

   Choose "Connect to the database" or "New Model Connected to the Database" will let you select your database and open the Connection Dialog.

   DbSchema automatically downloads the JDBC driver to connect to your database.

2. Configure the Connection

In the Connection Dialog window, select the JDBC URL you want to connect with. If your database is running in the cloud, choose Edit Manually and insert the JDBC URL from the cloud console.

Enter the host name, the authentication details, select your database as described in the Connection Dialog page.

3. Troubleshoot Firewall Issues
If you encounter connection issues, it may be due to firewall settings. Read how to enable Firewall Connections.

Connect to a Cloud MariaDB

All cloud providers, like AWS, Oracle or Google allows to get the JDBC URL in the cloud console. In DbSchema Connection Dialog choose 'Manually Edit the JDBC URL' and copy the URL.

Connect to a MariaDB Server

The Connection Dialog fields are explained on a dedicated page.

If you got problems connecting to MariaDb check the items below.

• Introduction
• Start MariaDb Service
• Enable Remote Connections
• Missing Privileges in MariaDb & Reset 'root' User Password
• Allow MariaDb through Windows Firewall
• What to Check on the Common Error Messages
• Guided MariaDb Installation on Windows

Introduction

Most of the commands in this article can be executed from MariaDb Command Line console. Start the console like this:

1. Open the command prompt by following this steps: Start -> run -> cmd -> press enter.
2. Navigate to your MariaDb installation folder (Default: C:\Program Files\MariaDb\MariaDb Server 12\bin)
3. Type in: mysql -u root -p

MariaDb users are a combination of username and host name allowed to connect ( can be '%' for any host). Check the current users and hosts allowed to connect, execute this from the mysql command prompt:

SELECT User, Host FROM mysql.user
+------+------------+
| User | Host       |
+------+------------+
| root | localhost  |
| user | %          |
+------+------------+
        

Localhost means it can connect only from the same computer, while % means it can connect from any computer. If MariaDb runs in a docker container the hosts are different ( like running on another computer ).

Enable MariaDb Service

If MariaDb service is not running, you won't be able to connect.

Windows
To enable MariaDb Service follow this steps:

1. Go to Start -> Control Panel -> System and Security -> Administrative Tools -> Component Services
   
   
2. Open Service Local
3. Find your MariaDb service name setup during installation (For Example: MariaDb56)
4. Right click on the service name and click start.
   
   

Linux
To start the MariaDb service on linux just type in the console: service mysqld start

Enable Remote Connectivity

Enabling remote connections require to enable TCP/IP connections in the configuration, and create a user allowed to connect from any host.

Enable TCP/IP Connectivity From Remote Hosts

To enable MariaDB to listen to remote connections, you need to edit your defaults file, located in DATADIR\my.ini (Windows) or /etc/my.cnf (Linux). Edit this configuration file and comment out the skip-networking line ( if any ) and set bind-address like this:

#skip-networking
bind-address = ::

Create a User Allowed to Connect from Remote Hosts

Check first which users are allowed to connect and from which hosts, using the query

SELECT User, Host FROM mysql.user

Create a new user allowed to connect from any hosts. Use '%' for any host or use a specific host IP.

CREATE USER 'dbschema'@'%' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON *.* TO 'sample'@'%';
FLUSH PRIVILEGES;

By default MariaDb already has an user 'root'@'localhost', with a password you should have already set during installation. This will work only for connections from the same machine. Docker containers are like different machines. Connecting from DbSchema you should use a different user, like 'dbschema', with % for all hosts or the specific host IP.

Grant Privileges on Specific Tables

GRANT ALL PRIVILEGES ON *.* TO 'USERNAME'@'IP' IDENTIFIED BY 'PASSWORD';
FLUSH PRIVILEGES;
quit

The privileges can be allowed on a specifc table using <DatabaseName>.<TableName>

Reset Password or Missing Privileges to Login

If you forgot the database user password you can follow this steps and reset it :

Windows

1. Shut down MySql or MariaDb service: Go to Start -> run -> services.msc -> MySQL -> right click and select STOP
2. Create a text file reset.txt. Im my case I save it under "C:\Temp\reset.txt". In this file paste the following lines:

   UPDATE mysql.user SET Password=PASSWORD('EnterPassword') WHERE User='root';
   FLUSH PRIVILEGES;
   

   Replace "EnterPassword" with your new password. Also make sure that the UPDATE and FLUSH commands are on separate lines!
   
   
3. Open the command prompt and navigate to your MySQL or MariaDb bin directory inside the program folder ("C:\Program Files\MySQL\MySQL Server 5.0\bin" or "C:\Program Files\MariaDb\bin")
   enter the following command

   mysqld.exe --init-file=C:\Temp\reset.txt --console
   

   This will replace your root password with the one you have set in the text file. The command may hang as the daemon continues to run. You can stop it ( Ctrl-C ) and start MySql again from Windows Services.
4. Restart MySQL Service: Start -> run -> services.msc -> MySQL > right click and select START
   

Linux

1. Log in as root and stop MariaDb service(daemon) by entering the command: service mysql stop
2. Start MariaDb service(daemon) and skip the grant tables which store the passwords by entering the command: mysqld_safe --skip-grant-tables
3. Now you should be able to connect to MariaDb without a password.Run the following commands:

   mysql --user=root mysql
   

   update user set Password=PASSWORD('new-password') where user='root';
   flush privileges;
   exit
   

4. Log in as root and start the MariaDb daemon by entering the command: service mysqld start

Enable Connections to Database through Windows Firewall

The common reason for connectivity problems is the error 'Communications link failure'. This is because during the MariaDb installation the checkbox to add an firewall exception was not enabled. To enable it later do as follow :

• Open Windows Firewall by clicking the Start button Picture of the Start button, and then clicking Control Panel. In the search box, type firewall, and then click Windows Firewall.
  
• In the left pane, click Advanced settings. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
  
• In the Windows Firewall with Advanced Security dialog box, in the left pane, click Inbound Rules, and then, in the right pane, click New Rule.
  
• Follow the instructions in the New Inbound Rule wizard. Make sure to select Add Port.
  
• For the Port name use MariaDb.
  
• For the specific local port use 3306
  
• Make sure to check off Allow the Connection
  
• For When does this rule apply?
  
• Put a check in Domain, private, and public.
  
• Make sure to follow the directions above for creating an Outbound rule...basically the same way except you click Outbound Rules on the left pane.
  

SSL Connections

If you wish to use ssl encryption, append this '?useSSL=true&verifyServerCertificate=false' to the URL Pattern in the JDBC Driver Manager.

Common Error Messages

Exception: Communications link failure. Exception: Communications link failure. The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

1. Check if the MariaDb Service on Server is Started
   
   
2. Check the MariaDb server port and hostname
   Test the connection using the PING button from the Connection Dialog.
   The default MariaDb port is 3306. However, this port can be changed for each MariaDb instance.
   Check the server files my.ini or my.cnf, in the mysqld section, to see the configured port, for example, port=3306.
   Find out the computer name right clicking My Computer and selecting Properties
   
   
3. Disable Firewalls on Server and Client
   Firewalls on client or server may block the connections. Configure them to accept incoming connections for MariaDb port or disable them.
   
   
4. Check the JDBC Driver Version
   DbSchema includes one JDBC driver for MariaDb. If the driver is not an actual version,
   search the internet for 'download MariaDb driver' or look on http://dev.mariadb.com/downloads/connector/j/
   You will probably download a file MariaDb-connector-java-x.x.x.zip.
   Decompress it and look for a file MariaDb-connector-java-x.x.x.jar. Upload this file in the in DbSchema JDBC Driver Manager.
   
   

• Exception: Test Connection Failed java.sql.SQLException: null, message from server: "Host 'YOUR_IP' is not allowed to connect to this MariaDb server"
Your ip is not allowed to connect to the MariaDb server.
• If the bind_address values is set to 127.0.0.1 in the MariaDb configuration file, the MariaDb server will not accept connections from remote hosts.
  The bind_address line in the MariaDb configuration file (my.ini or my.cnf) can either be removed or commented out to allow remote connections.

Guided MariaDb Installation on Windows

Download MariaDb

During the installation you have to enter the password for the database user root. Also you may want to enable access to MariaDb from remote computers

MariaDb Statements

• Create Database

      mysql -U root -p
      use <schema>;
      show tables;
      create database test;
      drop database test;
              

• Change Table Engine to Myisam

  ALTER TABLE schema.table ENGINE=Myisam;