The MariaDB Connector/Python module¶
MariaDB Connector/Python module enables python programs to access MariaDB and MySQL databases, using an API which is compliant with the Python DB API 2.0 (PEP-249).
Constructors¶
Connection¶
- connect(connectionclass=mariadb.connections.Connection, **kwargs)¶
Creates a MariaDB Connection object.
By default the standard connectionclass mariadb.connections.Connection will be created.
Parameter connectionclass specifies a subclass of mariadb.Connection object. If not specified default will be used. This optional parameter was added in version 1.1.0.
- Connection parameters are provided as a set of keyword arguments:
- host:
The host name or IP address of the database server. If MariaDB Connector/Python was built with MariaDB Connector/C 3.3 it is also possible to provide a comma separated list of hosts for simple fail over in case of one or more hosts are not available.
- user, username:
The username used to authenticate with the database server
- password, passwd:
The password of the given user
- database, db:
database (schema) name to use when connecting with the database server
- unix_socket:
The location of the unix socket file to use instead of using an IP port to connect. If socket authentication is enabled, this can also be used in place of a password.
- port:
port number of the database server. If not specified the default value of 3306 will be used.
- connect_timeout:
connect timeout in seconds
- read_timeout:
read timeout in seconds
- write_timeout:
write timeout in seconds
- local_infile:
Enables or disables the use of LOAD DATA LOCAL INFILE statements.
- compress= False:
Uses the compressed protocol for client server communication. If the server doesn’t support compressed protocol, the default protocol will be used.
- init_command:
Command(s) which will be executed when connecting and reconnecting to the database server
- default_file:
Read options from the specified option file. If the file is an empty string, default configuration file(s) will be used
- default_group:
Read options from the specified group
- plugin_dir:
Directory which contains MariaDB client plugins.
- reconnect:
Enables or disables automatic reconnect. Available since version 1.1.4
- ssl_key:
Defines a path to a private key file to use for TLS. This option requires that you use the absolute path, not a relative path. The specified key must be in PEM format
- ssl_cert:
Defines a path to the X509 certificate file to use for TLS. This option requires that you use the absolute path, not a relative path. The X609 certificate must be in PEM format.
- ssl_ca:
Defines a path to a PEM file that should contain one or more X509 certificates for trusted Certificate Authorities (CAs) to use for TLS. This option requires that you use the absolute path, not a relative path.
- ssl_capath:
Defines a path to a directory that contains one or more PEM files that contains one X509 certificate for a trusted Certificate Authority (CA)
- ssl_cipher:
Defines a list of permitted cipher suites to use for TLS
- ssl_crlpath:
Defines a path to a PEM file that should contain one or more revoked X509 certificates to use for TLS. This option requires that you use the absolute path, not a relative path.
- ssl_verify_cert:
Enables server certificate verification.
- ssl:
The connection must use TLS security or it will fail.
- tls_version:
A comma-separated list (without whitespaces) of TLS versions. Valid versions are TLSv1.0, TLSv1.1,TLSv1.2 and TLSv1.3. Added in version 1.1.7.
- autocommit=False:
Specifies the autocommit settings. True will enable autocommit, False will disable it (default).
- converter:
Specifies a conversion dictionary, where keys are FIELD_TYPE values and values are conversion functions
Note
For a description of configuration file handling and settings please read the chapter Configuration files of the MariaDB Connector/C documentation.
Example:
import mariadb
connection= mariadb.connect(user="example_user", host="localhost", database="test", password="GHbe_Su3B8")
print(connection.character_set)
Output:
utf8mb4
Connection Pool¶
- ConnectionPool(**kwargs)¶
Class defining a pool of database connections
MariaDB Connector/Python supports simple connection pooling. A connection pool holds a number of open connections and handles thread safety when providing connections to threads.
The size of a connection pool is configurable at creation time, but cannot be changed afterwards. The maximum size of a connection pool is limited to 64 connections.
Keyword Arguments:
pool_name (str) – Name of connection pool
pool_size (int)=5 – Size of pool. If not specified default value of 5 will be used. Maximum allowed number is 64.
pool_reset_connection (bool)=True – Will reset the connection before returning it to the pool. Default value is True.
pool_validation_interval (int)=500 – Specifies the validation interval in milliseconds after which the status of a connection requested from the pool is checked. The default values is 500 milliseconds, a value of 0 means that the status will always be checked. (Added in version 1.1.6)
Type constructors¶
- Binary()¶
Constructs an object capable of holding a binary value.
- Date(year, month, day)¶
Constructs an object holding a date value.
- DateFromTicks(ticks)¶
Constructs an object holding a date value from the given ticks value (number of seconds since the epoch). For more information see the documentation of the standard Python time module.
- Time(hour, minute, second)¶
Constructs an object holding a time value.
- TimeFromTicks(ticks)¶
Constructs an object holding a time value from the given ticks value (number of seconds since the epoch). For more information see the documentation of the standard Python time module.
- Timestamp(year, month, day, hour, minute, second)¶
Constructs an object holding a datetime value.
- TimestampFromTicks(ticks)¶
Constructs an object holding a datetime value from the given ticks value (number of seconds since the epoch). For more information see the documentation of the standard Python time module.
Attributes¶
- apilevel¶
String constant stating the supported DB API level. The value for mariadb is
2.0
.
- threadsafety¶
Integer constant stating the level of thread safety. For mariadb the value is 1, which means threads can share the module but not the connection.
- paramstyle¶
String constant stating the type of parameter marker. For mariadb the value is qmark. For compatibility reasons mariadb also supports the format and pyformat paramstyles with the limitation that they can’t be mixed inside a SQL statement.
- mariadbapi_version¶
String constant stating the version of the used MariaDB Connector/C library.
Added in version 1.1.0.
- client_version¶
Returns the version of MariaDB Connector/C library in use as an integer. The number has the following format: MAJOR_VERSION * 10000 + MINOR_VERSION * 1000 + PATCH_VERSION
Added in version 1.1.0.
- client_version_info¶
Returns the version of MariaDB Connector/C library as a tuple in the following format: (MAJOR_VERSION, MINOR_VERSION, PATCH_VERSION)
Exceptions¶
Compliant to DB API 2.0 MariaDB Connector/C provides information about errors through the following exceptions:
- exception DataError¶
Exception raised for errors that are due to problems with the processed data like division by zero, numeric value out of range, etc.
- exception DatabaseError¶
Exception raised for errors that are related to the database
- exception InterfaceError¶
Exception raised for errors that are related to the database interface rather than the database itself
- exception Warning¶
Exception raised for important warnings like data truncations while inserting, etc
- exception PoolError¶
Exception raised for errors related to ConnectionPool class.
- exception OperationalError¶
Exception raised for errors that are related to the database’s operation and not necessarily under the control of the programmer.
- exception IntegrityError¶
Exception raised when the relational integrity of the database is affected, e.g. a foreign key check fails
- exception InternalError¶
Exception raised when the database encounters an internal error, e.g. the cursor is not valid anymore
- exception ProgrammingError¶
Exception raised for programming errors, e.g. table not found or already exists, syntax error in the SQL statement
- exception NotSupportedError¶
Exception raised in case a method or database API was used which is not supported by the database
Type objects¶
MariaDB Connector/Python type objects are immutable sets for type settings and defined in DBAPI 2.0 (PEP-249).
Example:
import mariadb
from mariadb.constants import FIELD_TYPE
print(FIELD_TYPE.GEOMETRY == mariadb.BINARY)
print(FIELD_TYPE.DATE == mariadb.DATE)
print(FIELD_TYPE.VARCHAR == mariadb.BINARY)
Output:
True
True
False
- STRING¶
This type object is used to describe columns in a database that are string-based (e.g. CHAR1).
- BINARY¶
This type object is used to describe (long) binary columns in a database (e.g. LONG, RAW, BLOBs).
- NUMBER¶
This type object is used to describe numeric columns in a database.
- DATETIME¶
This type object is used to describe date/time columns in a database.
- ROWID¶
This type object is not supported in MariaDB Connector/Python and represents an empty set.