In this section, you’ll find how to add new integrations/databases to MindsDB.
Prerequisite
You should have the latest staging version of the MindsDB repository installed locally. Follow this guide to learn how to install MindsDB for development.
Database handlers act as a bridge to any database. You use database handlers to create databases using the CREATE DATABASE command. So you can reach data from any database that has its handler implemented within MindsDB.
ML Handlers
To learn more about handlers and how to implement a machine learning (ML) handler, visit our doc page here.
You can create your own database handler within MindsDB by inheriting from the DatabaseHandler
class.
By providing the implementation for some or all of the methods contained in the DatabaseHandler
class, you can connect with the database of your choice.
Apart from the __init__()
method, there are seven core methods that must be implemented. We recommend checking actual examples in the codebase to get an idea of what goes into each of these methods, as they can change a bit depending on the nature of the system being integrated.
Let’s review the purpose of each method.
Method | Purpose |
---|---|
connect() | It performs the necessary steps to connect to the underlying system. |
disconnect() | It gracefully closes connections established in the connect() method. |
check_connection() | It evaluates if the connection is alive and healthy. This method is called frequently. |
native_query() | It parses any native statement string and acts upon it (for example, raw SQL commands). |
query() | It takes a parsed SQL command in the form of an abstract syntax tree and executes it. |
get_tables() | It lists and returns all the available tables. Each handler decides what a table means for the underlying system when interacting with it from the data layer. Typically, these are actual tables. |
get_columns() | It returns columns of a table registered in the handler with the respective data type. |
Authors can opt for adding private methods, new files and folders, or any combination of these to structure all the necessary work that will enable the core methods to work as intended.
Other Common Methods
Under the mindsdb.integrations.libs.utils
library, contributors can find various methods that may be useful while implementing new handlers.
Also, there are wrapper classes for the DatabaseHandler
instances called HandlerResponse and HandlerStatusResponse. You should use them to ensure proper output formatting.
Each database handler should inherit from the DatabaseHandler
class.
Here is a step-by-step guide:
Setting the name
class property:
MindsDB uses it internally as the name of the handler.
For example, the CREATE DATABASE
statement uses the handler’s name.
Implementing the __init__()
method:
This method initializes the handler. The connection_data
argument contains the PARAMETERS
from the CREATE DATABASE
statement, such as user
, password
, etc.
Implementing the connect()
method:
The connect()
method sets up the connection.
Implementing the disconnect()
method:
The disconnect()
method closes the existing connection.
Implementing the check_connection()
method:
The check_connection()
method performs the health check for the connection.
Implementing the native_query()
method:
The native_query()
method runs commands of the native database language.
Implementing the query()
method:
The query method runs parsed SQL commands.
Implementing the get_tables()
method:
The get_tables()
method lists all the available tables.
Implementing the get_columns()
method:
The get_columns()
method lists all columns of a specified table.
connection_args
DictionaryThe connection_args
dictionary contains all of the arguments used to establish the connection along with their descriptions, types, labels, and whether they are required or not.
Here is an example of the connection_args
dictionary from the MySQL handler.
connection_args_example
DictionaryThe connection_args_example
dictionary contains an example of all required arguments to establish the connection.
Here is an example of the connection_args_example
dictionary from the MySQL handler.
The following should be exported in the __init__.py
file of the handler:
Handler
class.version
of the handler.name
of the handler.type
of the handler, either DATA
handler or ML
handler.icon_path
to the file with the database icon.title
of the handler or a short description.description
of the handler.connection_args
dictionary with the connection arguments.connection_args_example
dictionary with an example of the connection arguments.import_error
message that is used if the import of the Handler
class fails.A few of these variables are defined in another file called __about__.py
. This file is imported into the __init__.py
file.
Here is an example of the __init__.py
file for the MySQL handler.
The __about__.py
file for the same MySQL handler contains the following variables:
To see some integration handlers that are currently in use, we encourage you to check out the following handlers inside the MindsDB repository:
And here are all the handlers available in the MindsDB repository.