Connect with MariaDB Connector/C++

Overview

MariaDB Connector/C++ enables C++ applications to establish client connections to MariaDB database products over TLS.

Connection Info

The connection is configured via the information that is initially acquired from the SkySQL Portal pages:

What to set

Where to find it

Hostname in the URL

The fully Qualified Domain Name in the Service Details view

Port number in the URL

The Read-Write Port or Read-Only Port in the Service Details view

user parameter

The desired username, which might be the default username in the Service Credentials view

password parameter

The user's password, which might be the default password in the Service Credentials view if it was not yet customized

tlsCert parameter

The path to the skysql_chain.pem file containing the "Certificate Authority Chain"

Connection URL Syntax

MariaDB Connector/C++ supports two different formats for connection URLs, the JDBC syntax and the compatibility syntax.

While MariaDB Connector/C++ supports several connection styles, we are going to detail just the JDBC syntax since all connections to SkySQL use a single idiom of hostname, port, user, password, and SSL parameters.

The base URL is specified as follows:

jdbc:mariadb://example.skysql.net:5001/dbname

If the trailing database name is left off of the URL, the connection will start without selecting a database.

JDBC Syntax

MariaDB Connector/C++ supports a connection URL syntax similar to JDBC.

The JDBC syntax for connection URLs is:

jdbc:mariadb://<hostDescription>/[<database>] [?<key1>=<value1>[&<key2>=<value2>]]

The connection URL:

  • Requires jdbc:mariadb:// as the protocol component.

  • Requires the host description in the hostDescription field.

  • Accepts an optional database name. If no database is provided, the connection will not select a database.

  • Accepts optional connection parameters in key=value format.

Some example connection URLs using the JDBC syntax:

  • jdbc:mariadb://192.0.2.1/

  • jdbc:mariadb://192.0.2.1/?user=db_user&password=db_user_password

  • jdbc:mariadb://192.0.2.1/database?user=db_user&password=db_user_password

  • jdbc:mariadb://192.0.2.1:3307/database?user=db_user&password=db_user_password

  • jdbc:mariadb://mariadb.example.com/database?user=db_user&password=db_user_password

  • jdbc:mariadb://mariadb.example.com:3307/database?user=db_user&password=db_user_password

  • jdbc:mariadb://localhost/database?localSocket=/var/lib/mysql/mysql.sock&user=db_user&password=db_user_password

Compatibility Syntax

MariaDB Connector/C++ supports a connection URL syntax for compatibility with MySQL Connector/C++.

The compatibility syntax for connection URLs is only supported for the sql::Driver::connect() connection method.

The compatibility syntax for connection URLs is:

(tcp|unix|pipe)://<hostDescription>[/]

The connection URL:

  • Requires tcp:// as the protocol component to connect via TCP/IP.

  • Requires unix:// as the protocol component to connect via Unix socket file. The hostDescription field should be set to localhost, and the localSocket connection parameter should be set in the properties when you call the sql::Driver::connect() connection method.

  • Requires pipe:// as the protocol component to connect via Windows named pipe. The hostDescription field should be set to localhost, and the pipe connection parameter should be set in the properties when you call the sql::Driver::connect() connection method.

  • Requires the host description in the hostDescription field.

Some example connection URLs using the compatibility syntax:

  • tcp://192.0.2.1/

  • tcp://192.0.2.1:3307/

  • tcp://mariadb.example.com/

  • tcp://mariadb.example.com:3307/

  • unix://localhost/

  • pipe://localhost/

Host Description

The host description syntax for MariaDB Connector/C++ is:

<host>[:<portNumber>]

The host description:

  • Requires the host field to set the destination host to connect.

  • Accepts the host field as a host name, IPv4 address, or IPv6 address to connect via TCP/IP.

  • Accepts the host field as localhost to connect via Unix socket file, when the localSocket connection parameter is also set.

  • Accepts an optional portNumber field to set the TCP/IP port. If it is not provided, the TCP port 3306 is used by default.

Some example host descriptions:

  • 192.0.2.1

  • 192.0.2.1:3307

  • mariadb.example.com

  • mariadb.example.com:3307

jdbc:mariadb://192.0.2.1:3306/database?user=db_user&password=db_user_password

Optional Connection Parameters

MariaDB Connector/C++ accepts optional connection parameters in multiple contexts for both connection methods:

MariaDB Connector/C++ supports several optional connection parameters. These parameters can be specified using a Properties object, as we do in our examples, or appended to the URL in standard name=value query-string encoding.

MariaDB Connector/C++ supports several optional connection parameters:

In the following list, we've left out any parameters that aren't pertinent to accessing SkySQL:

Parameter Name

Description

Type

Default

Aliases

autoReconnect

Defines whether the connector automatically reconnects after a connection failure.

bool

false

  • OPT_RECONNECT

cachePrepStmts

Defines whether the prepared statement cache is enabled.

bool

false

connectTimeout

Defines the connect timeout value in milliseconds. When set to 0, there is no connect timeout.

int

30000

enabledTlsCipherSuites

A list of permitted ciphers or cipher suites to use for TLS.

string

  • enabledSslCipherSuites

  • enabledSSLCipherSuites

hostName

The host name, IPv4 address, or IPv6 address to connect via TCP/IP. This parameter is only supported by the sql::Driver::connect() connection method that does not use a connection URL. If a connection URL is provided, the host name, IPv4 address, or IPv6 address should be specified in the connection URL.

jdbcCompliantTruncation

This mode is enabled by default. This mode configures the connector to add STRICT_TRANS_TABLES to sql_mode, which causes ES to handle truncation issues as errors instead of warnings.

bool

true

keyPassword

Password for the private key.

string

  • MARIADB_OPT_TLS_PASSPHRASE

localSocket

Defines the Unix socket file to use for connections to localhost via Unix domain socket. Specify the path of Unix socket file, which can be obtained by querying the socket system variable: SHOW GLOBAL VARIABLES LIKE 'socket';

string

log

Non-zero value turns on logging and determines logging level.

  • 0 = no logging

  • 1 = error

  • 2 = warning

  • 3 = info

  • 4 = debug

  • 5 = trace

int

0

logname

The name of file to write the log in. If logname set, and log is not, log will be set to 1(error). Default name is mariadbccpp.log, and it's written to %TEMP% or %USERPROFILE% or current dir on Windows, and in $HOME or in /tmp on other systems. Logging is synchronized between threads, but not between processes.

string

mariadbccpp.log

password

Defines the password of the user account to connect with.

pipe

Defines the name of the named pipe to use for connections to localhost via named pipe on Windows. Specify the name of the named pipe, which is MySQL by default.

string

prepStmtCacheSize

Defines the number of prepared statements that are cached for each connection. This parameter only applies if cachePrepStmts is enabled.

int

250

prepStmtCacheSqlLimit

Defines the maximum length for a prepared statement in the cache. This parameter only applies if cachePrepStmts is enabled. This value consists of length of query itself + length of schema name + 1

int

2048

rewriteBatchedStatements

An optimized mode of executeBatch/executeLargeBatch PreparedStatement methods execution. For INSERT queries, the connector will construct a single query using batch parameter sets. If used with useBulkStmts, rewriteBatchedStatements takes precedence.

schema

The database to select for the connection. If no database is provided, the connection will not select a database. This parameter is only supported by the sql::Driver::connect() connection method that does not use a connection URL. If a connection URL is provided, the database should be specified in the connection URL.

serverRsaPublicKeyFile

The name of the file that contains the RSA public key of the database server. The format of this file must be in PEM format. This option is used by the caching_sha2_password client authentication plugin.

string

  • rsaKey

socketTimeout

Defines the network socket timeout (SO_TIMEOUT) in milliseconds. When set to 0, there is no socket timeout. This connection parameter is not intended to set a maximum time for statements. To set a maximum time for statements, please see the max_statement_time system variable.

int

0

  • OPT_READ_TIMEOUT

tcpRcvBuf

The buffer size for TCP/IP and socket communication. tcpSndBuf changes the same buffer value, and the biggest value of the two is selected.

int

0x4000

  • tcpSndBuf

tcpSndBuf

The buffer size for TCP/IP and socket communication. tcpRcvBuf changes the same buffer value, and the biggest value of the two is selected.

int

0x4000

  • tcpRcvBuf

tlsCA

A path to a PEM file that should contain one or more X509 certificates for trusted Certificate Authorities (CAs).

string

  • tlsCa

  • sslCA

tlsCAPath

A path to a directory that contains one or more PEM files that should each contain one X509 certificate for a trusted Certificate Authority (CA) to use. The directory specified by this option must be processed by the openssl rehash command. This option is only supported if the connector was built with OpenSSL.

string

  • tlsCaPath

  • sslCAPath

tlsCert

Path to the X509 certificate file.

string

  • sslCert

tlsCRL

Path to a PEM file that should contain one or more revoked X509 certificates.

string

  • tlsCrl

  • sslCRL

tlsCRLPath

A path to a directory that contains one or more PEM files that should each contain one revoked X509 certificate. The directory specified by this option must be processed by the openssl rehash command. This option is only supported if the connector was built with OpenSSL.

string

  • tlsCrlPath

  • sslCRLPath

tlsKey

File path to a private key file.

string

  • sslKey

tlsPeerFP

A SHA1 fingerprint of a server certificate for validation during the TLS handshake.

string

  • tlsPeerFp

  • MARIADB_OPT_SSL_FP

tlsPeerFPList

A file containing one or more SHA1 fingerprints of server certificates for validation during the TLS handshake.

string

  • tlsPeerFpList

  • MARIADB_OPT_SSL_FP_LIST

useBulkStmts

An optimized mode of executeBatch/executeLargeBatch PreparedStatement methods execution that uses the MariaDB bulk execution feature. If used with rewriteBatchedStatements, rewriteBatchedStatements takes precedence.

useCompression

Compresses network traffic between the client and server.

bool

false

  • CLIENT_COMPRESS

user

Defines the user name of the user account to connect with.

useServerPrepStmts

Defines whether the connector uses server-side prepared statements using the PREPAREPREPARE, EXECUTEEXECUTE, and DROP PREPAREDROP PREPARE statements. By default, the connector uses client-side prepared statements.

bool

false

useTls

Whether to force TLS. This enables TLS with the default system settings.

bool

  • useSsl

  • useSSL

Connection Methods

Two categories of methods are available to to establish a connection.

sql::Driver::connect()

MariaDB Connector/C++ can connect using the non-static connect() methods in the sql::Driver class.

The non-static connect() methods in the sql::Driver class have the following prototypes:

  • Connection* connect(const SQLString& url, Properties& props);

  • Connection* connect(const SQLString& host, const SQLString& user, const SQLString& pwd);

  • Connection* connect(const Properties& props);

The non-static connect() methods in the sql::Driver class:

  • Require an instance of the sql::Driver class to establish a connection.

  • Accept both forms of connection URL syntax.

  • Provide two prototypes that do not use connection URLs at all.

  • Return nullptr as the Connection* value when an error occurs, so applications should check the return value before use.

For example:

// Instantiate Driver
sql::Driver* driver = sql::mariadb::get_driver_instance();

// Configure Connection
// The URL or TCP connection string format is
// ``jdbc:mariadb://host:port/database``.
sql::SQLString url("jdbc:mariadb://192.0.2.1:3306/test");

// Use a properties map for the other connection options
sql::Properties properties({
      {"user", "db_user"},
      {"password", "db_user_password"},
   });

// Establish Connection
// Use a smart pointer for extra safety
std::unique_ptr<sql::Connection> conn(driver->connect(url, properties));

if (!conn) {
   cerr << "Invalid database connection" << endl;
   exit (EXIT_FAILURE);
}

// Instantiate Driver
sql::Driver* driver = sql::mariadb::get_driver_instance();

// Configure Connection, including an optional initial database name "places":
sql::SQLString url("jdbc:mariadb://example.skysql.net:5009/places");

// Use a properties map for the other connection options
sql::Properties properties({
      {"user", "db_user"},
      {"password", "db_user_password"},
      {"autocommit", false},
      {"useTls", true},
      {"tlsCert", "classpath:static/skysql_chain.pem"},
   });

// Establish Connection
// Use a smart pointer for extra safety
std::unique_ptr<sql::Connection> conn(driver->connect(url, properties));

if (!conn) {
   cerr << "Invalid database connection" << endl;
   exit (EXIT_FAILURE);
}

sql::DriverManager::getConnection()

MariaDB Connector/C++ can connect using the static getConnection() methods in the sql::DriverManager class.

The static getConnection() methods in the sql::DriverManager class have the following prototypes:

  • static Connection* getConnection(const SQLString& url);

  • static Connection* getConnection(const SQLString& url, Properties& props);

  • static Connection* getConnection(const SQLString& url, const SQLString& user, const SQLString& pwd);

The static getConnection() methods in the sql::DriverManager class:

  • Do not require an instance of the sql::DriverManager class to establish a connection, because they are static.

  • Throw an exception when an error occurs, so applications should use try { .. } catch ( .. ) { .. } to catch the exception.

For example:

 try {
    // Configure Connection
    // The URL or TCP connection string format is
    // ``jdbc:mariadb://host:port/database``.
    sql::SQLString url("jdbc:mariadb://192.0.2.1:3306/test");

    // Use a properties map for the other connection options
    sql::Properties properties({
          {"user", "db_user"},
          {"password", "db_user_password"},
       });

    // Establish Connection
    // Use a smart pointer for extra safety
    std::unique_ptr<sql::Connection> conn(DriverManager::getConnection(url, properties));
 } catch (...) {
    cerr << "Invalid database connection" << endl;
    exit (EXIT_FAILURE);
}

 try {
    // Configure Connection, including an optional initial database name "places":
    sql::SQLString url("jdbc:mariadb://example.skysql.net:5009/places");

    // Use a properties map for the other connection options
    sql::Properties properties({
          {"user", "db_user"},
          {"password", "db_user_password"},
          {"autocommit", false},
          {"useTls", true},
          {"tlsCert", "classpath:static/skysql_chain.pem"},
       });

    // Establish Connection
    // Use a smart pointer for extra safety
    std::unique_ptr<sql::Connection> conn(DriverManager::getConnection(url, properties));
 } catch (...) {
    cerr << "Invalid database connection" << endl;
    exit (EXIT_FAILURE);
}

Code Example: Connect

The following code demonstrates how to connect using the example database and user account:

// Includes
#include <iostream>
#include <mariadb/conncpp.hpp>

// Main Process
int main(int argc, char **argv)
{
   try {
      // Instantiate Driver
      sql::Driver* driver = sql::mariadb::get_driver_instance();

      // Configure Connection
      // The URL or TCP connection string format is
      // ``jdbc:mariadb://host:port/database``.
      sql::SQLString url("jdbc:mariadb://192.0.2.1:3306/test");

      // Use a properties map for the other connection options
      sql::Properties properties({
            {"user", "db_user"},
            {"password", "db_user_password"},
         });

      // Establish Connection
      // Use a smart pointer for extra safety
      std::unique_ptr<sql::Connection> conn(driver->connect(url, properties));

      // Use Connection
      // ...

      // Close Connection
      conn->close();
   }

   // Catch Exceptions
   catch (sql::SQLException& e) {
      std::cerr << "Error Connecting to the database: "
         << e.what() << std::endl;

      // Exit (Failed)
      return 1;
   }

   // Exit (Success)
   return 0;
}

// Includes
#include <iostream>
#include <mariadb/conncpp.hpp>

// Main Process
int main(int argc, char **argv)
{
   try {
      // Instantiate Driver
      sql::Driver* driver = sql::mariadb::get_driver_instance();

      // Configure Connection, including initial database name "test":
      sql::SQLString url("jdbc:mariadb://example.skysql.net:5009/test");

      // Use a properties map for the other connection options
      sql::Properties properties({
            {"user", "db_user"},
            {"password", "db_user_password"},
            {"autocommit", false},
            {"useTls", true},
            {"tlsCert", "classpath:static/skysql_chain.pem"},
         });

      // Establish Connection
      // Use a smart pointer for extra safety
      std::unique_ptr<sql::Connection> conn(driver->connect(url, properties));

      // Use Connection
      // ...

      // Close Connection
      conn->close();
   }

   // Catch Exceptions
   catch (sql::SQLException& e) {
      std::cerr << "Error Connecting to the database: "
         << e.what() << std::endl;

      // Exit (Failed)
      return 1;
   }

   // Exit (Success)
   return 0;
}

Code Example: TLS

The following code demonstrates how to connect with TLS (Transport Layer Security, the successor to SSL) for the example database and user account:

// Includes
#include <iostream>
#include <mariadb/conncpp.hpp>

// Main Process
int main(int argc, char **argv)
{
   try {
      // Instantiate Driver
      sql::Driver* driver = sql::mariadb::get_driver_instance();

      // Configure Connection
      // The URL or TCP connection string format is
      // ``jdbc:mariadb://host:port/database``.
      sql::SQLString url("jdbc:mariadb://192.0.2.1:3306/test");

      // Use a properties map for the user name and password
      //The ``useTls`` option enables TLS
      //The ``tlsCA`` option specifies path to a PEM file that contains a X509 certificate for trusted Certificate Authorities (CAs).
      sql::Properties properties({
            {"user", "db_user"},
            {"password", "db_user_password"},
            {"useTls", "true"},
            {"tlsCA", "tls-ca-root.pem"}
         });

      // Establish Connection
      // Use a smart pointer for extra safety
      std::unique_ptr<sql::Connection> conn(driver->connect(url, properties));

      // Use Connection
      // ...

      // Close Connection
      conn->close();
   }

   // Catch Exceptions
   catch (sql::SQLException& e) {
      std::cerr << "Error Connecting to the database: "
         << e.what() << std::endl;

      // Exit (Failed)
      return 1;
   }

   // Exit (Success)
   return 0;
}