> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/connectors/mariadb-connector-c/api-functions.md). # MariaDB Connector/C API Functions The MariaDB Connector/C API provides functions for establishing connections, executing statements, retrieving and navigating result sets, managing transactions, and configuring connection options, plugins, and metadata. ## Function Overview | Function | Description | | -------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | [`mariadb_cancel()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_cancel.md) | Immediately aborts a connection by making all subsequent read/write operations fail, without freeing the MYSQL structure or closing communication channels. | | [`mariadb_connect()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_connect.md) | Connect to a database server using a connection string. | | [`mariadb_connection()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_connection.md) | Checks whether the client is currently connected to a MariaDB or MySQL server. | | [`mariadb_convert_string()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_convert_string.md) | Converts a string to a different character set. | | [`mariadb_field_attr()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_field_attr.md) | Returns extended metadata for pluggable field types such as JSON and GEOMETRY. | | [`mariadb_get_info()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_get_info.md) | Retrieves generic or connection-related information. | | [`mariadb_get_infov()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_get_infov.md) | Retrieves generic or connection-specific information from a MariaDB Connector/C handle, accepting a value-type enum and a pointer to store the result. | | [`mariadb_reconnect()`](/docs/connectors/mariadb-connector-c/api-functions/mariadb_reconnect.md) | Attempts to re-establish a dropped MariaDB Connector/C connection using the original credentials, and requires the MYSQL\_OPT\_RECONNECT option to be set. | | [`mysql_affected_rows()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_affected_rows.md) | Returns the number of rows affected by the last INSERT, UPDATE, DELETE, or REPLACE statement executed on a MariaDB Connector/C connection. | | [`mysql_autocommit()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_autocommit.md) | Enables or disables autocommit mode for the current database connection, returning zero on success or nonzero on failure. | | [`mysql_change_user()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_change_user.md) | Changes the authenticated user and default database on an existing connection, resetting session state including transactions, temporary tables, and locks. | | [`mysql_character_set_name()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_character_set_name.md) | Returns the name of the default client character set for a specified MariaDB Connector/C connection. | | [`mysql_client_find_plugin()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_client_find_plugin.md) | Returns a handle to an already-loaded client plugin of the given name and type. | | [`mysql_close()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_close.md) | Terminates an open database connection and releases the memory allocated for the MYSQL handle. | | [`mysql_commit()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_commit.md) | Commits the current transaction on a MariaDB Connector/C connection, returning zero on success without affecting autocommit mode. | | [`mysql_data_seek()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_data_seek.md) | Moves the result set pointer to an arbitrary row offset in a buffered result set obtained via mysql\_store\_result, enabling random row access. | | [`mysql_debug()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_debug.md) | Enables debug output for a MariaDB Connector/C client using the DBUG library, accepting a colon-separated control string to configure trace and logging options. | | [`mysql_dump_debug_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_dump_debug_info.md) | Instructs a MariaDB server to write connection status information to the error log, and requires the SUPER privilege for the current user. | | [`mysql_eof()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_eof.md) | Determines whether the final row in a result set has already been retrieved. (Deprecated.) | | [`mysql_errno()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_errno.md) | Returns the numeric error code from the most recent MariaDB Connector/C function call, or zero if no error occurred. | | [`mysql_error()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_error.md) | Returns the error message string for the most recent failed MariaDB Connector/C function call, or an empty string if no error occurred. | | [`mysql_escape_string()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_escape_string.md) | Encodes a string using the default character set for safe use in SQL statements. Deprecated — use mysql\_real\_escape\_string instead. | | [`mysql_fetch_field()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_fetch_field.md) | Returns the definition of one result set column as a MYSQL\_FIELD pointer; call it repeatedly to iterate over all columns in the result set. | | [`mysql_fetch_field_direct()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_fetch_field_direct.md) | Returns a MYSQL\_FIELD pointer for a specific column in a result set, identified by its zero-based field number. | | [`mysql_fetch_fields()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_fetch_fields.md) | Returns all column definitions for a MariaDB result set as an array of MYSQL\_FIELD structures, one entry per column. | | [`mysql_fetch_lengths()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_fetch_lengths.md) | Returns an array of byte lengths for each column in the current row of a MariaDB result set, valid only after mysql\_fetch\_row is called. | | [`mysql_fetch_row()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_fetch_row.md) | Retrieves the next row from a MariaDB result set as an array of char pointers, returning NULL when no more rows are available. | | [`mysql_field_count()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_field_count.md) | Returns the number of columns in the most recent query result for a MariaDB connection, useful for checking whether a result set is available. | | [`mysql_field_seek()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_field_seek.md) | Sets the field cursor to a given column offset in a MariaDB result set, controlling which field mysql\_fetch\_field returns next. | | [`mysql_field_tell()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_field_tell.md) | Retrieves the current field cursor position in a result set, which can be passed to mysql\_field\_seek to restore that position. | | [`mysql_free_result()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_free_result.md) | Releases the memory allocated for a MariaDB result set; row values obtained from prior mysql\_fetch\_row calls become invalid after this call. | | [`mysql_get_character_set_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_character_set_info.md) | Populates a MY\_CHARSET\_INFO structure with details about the current default character set for a MariaDB Connector/C connection. | | [`mysql_get_client_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_client_info.md) | Retrieves the client library version as a string; use mysql\_get\_client\_version for the equivalent numeric value. | | [`mysql_get_client_version()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_client_version.md) | Retrieves the client library version as an unsigned long; use mysql\_get\_client\_info for the string representation. | | [`mysql_get_host_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_host_info.md) | Returns a string describing the connection type and server hostname for a MariaDB Connector/C connection, or NULL if invalid. | | [`mysql_get_optionv()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_optionv.md) | Retrieves the current value of a connection option previously set with mysql\_optionsv, supporting boolean, integer, string, and miscellaneous option types. | | [`mysql_get_proto_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_proto_info.md) | Returns the protocol version number used for a MariaDB Connector/C connection; versions 9 and below are not supported. | | [`mysql_get_server_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_server_info.md) | Retrieves the connected server version string; use mysql\_get\_server\_version for the equivalent numeric representation. | | [`mysql_get_server_version()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_server_version.md) | Retrieves the server version as an unsigned long; use mysql\_get\_server\_info for the equivalent string representation. | | [`mysql_get_ssl_cipher()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_ssl_cipher.md) | Returns the name of the TLS cipher in use for a MariaDB Connector/C connection, or NULL for non-TLS connections. | | [`mysql_get_timeout_value()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_timeout_value.md) | Retrieves the timeout value configured for asynchronous operations, in seconds. | | [`mysql_get_timeout_value_ms()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_get_timeout_value_ms.md) | Retrieves the timeout value configured for asynchronous operations, in milliseconds. | | [`mysql_hex_string()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_hex_string.md) | Converts a binary buffer to a hex-encoded string for safe embedding in SQL; the output buffer must be at least 2\*length+1 bytes. | | [`mysql_info()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_info.md) | Returns a string with summary statistics about the last executed query, covering INSERT, UPDATE, ALTER TABLE, and LOAD DATA operations; returns NULL for SELECT. | | [`mysql_init()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_init.md) | Allocates and initializes a MYSQL structure for use with mysql\_real\_connect, and also initializes the thread subsystem if not already done. | | [`mysql_insert_id()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_insert_id.md) | Returns the AUTO\_INCREMENT value generated by the last INSERT or UPDATE statement on a MariaDB connection, or zero if no such value was produced. | | [`mysql_kill()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_kill.md) | Requests the MariaDB server to terminate the thread with the given process ID; use mysql\_thread\_id to obtain the ID of the current connection. | | [`mysql_load_plugin()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_load_plugin.md) | Loads a client plugin of the given name and type from the client plugin directory. | | [`mysql_library_end()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_library_end.md) | Finalizes the MariaDB Connector/C library after use, performing memory cleanup and shutting down the embedded server if applicable. | | [`mysql_library_init()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_library_init.md) | Initializes the MariaDB Connector/C library before any other functions are called, starting the embedded server if used in that configuration. | | [`mysql_more_results()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_more_results.md) | Indicates whether additional result sets remain from a previous multi-statement query, returning 1 if more results are available. | | [`mysql_net_field_length()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_net_field_length.md) | Returns the length of a length-encoded field and advances the pointer past it. | | [`mysql_net_read_packet()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_net_read_packet.md) | Reads the next protocol packet from the server into the connection's network buffer. | | [`mysql_next_result()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_next_result.md) | Advances to the next result set from a multi-statement query, making it available for retrieval via mysql\_store\_result or mysql\_use\_result. | | [`mysql_num_fields()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_num_fields.md) | Retrieves the column count from a result set handle, useful for iterating over fields in a MariaDB query result. | | [`mysql_num_rows()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_num_rows.md) | Returns the number of rows in a MariaDB result set; for unbuffered results the count is only accurate after all rows have been fetched. | | [`mysql_options4()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_options4.md) | Sets extra connection options that take two arguments; call after mysql\_init() and before mysql\_real\_connect(). | | [`mysql_options()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_options.md) | Sets extra connection options on a MYSQL handle before calling mysql\_real\_connect. Deprecated since Connector/C 3.0 — use mysql\_optionsv instead. | | [`mysql_optionsv()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_optionsv.md) | Sets connection, TLS, plugin, and option-file options on a MariaDB Connector/C handle before mysql\_real\_connect, supporting a variable argument list. | | [`mysql_ping()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_ping.md) | Checks whether a MariaDB server connection is still active and attempts an automatic reconnect if the connection has dropped and reconnect is enabled. | | [`mysql_query()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_query.md) | Sends a null-terminated SQL string to the MariaDB server for execution, returning zero on success; use mysql\_real\_query for binary-safe operation. | | [`mysql_read_query_result()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_read_query_result.md) | Reads the result of a statement previously sent with mysql\_send\_query, and must be called once for each successful mysql\_send\_query call. | | [`mysql_real_connect()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_real_connect.md) | Opens a connection to a MariaDB server and returns a MYSQL handle on success, or NULL if the connection could not be established. | | [`mysql_real_escape_string()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_real_escape_string.md) | Encodes a string for safe use in a SQL statement, taking the connection's current character set into account when escaping special characters. | | [`mysql_real_query()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_real_query.md) | Sends a binary-safe SQL statement to a MariaDB server; use mysql\_num\_fields to determine whether the query returned a result set. | | [`mysql_refresh()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_refresh.md) | Flushes server-side caches and state using a bitmask of options such as REFRESH\_GRANT, REFRESH\_LOG, REFRESH\_TABLES, and REFRESH\_HOSTS. | | [`mysql_reset_connection()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_reset_connection.md) | Resets session state on a MariaDB Connector/C connection — rolling back transactions and clearing variables — without disconnecting or reauthenticating. | | [`mysql_rollback()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_rollback.md) | Undoes the current transaction for a database connection; it has no effect if autocommit is enabled or the engine is non-transactional. | | [`mysql_row_seek()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_row_seek.md) | Repositions the row cursor in a buffered MariaDB result set to an arbitrary offset, returning the previous row position as a MYSQL\_ROW\_OFFSET. | | [`mysql_row_tell()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_row_tell.md) | Returns the current row cursor offset for a buffered MariaDB result set, which can then be passed to mysql\_row\_seek to restore that position. | | [`mysql_select_db()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_select_db.md) | Changes the default database on an active connection; the current default can also be queried with the SELECT DATABASE() SQL function. | | [`mysql_send_query()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_send_query.md) | Dispatches a query asynchronously on a MariaDB connection; each call must be followed by mysql\_read\_query\_result to consume the response. | | [`mysql_server_end()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_server_end.md) | Is an alias for mysql\_library\_end in MariaDB Connector/C, used to finalize and clean up the client library. | | [`mysql_server_init()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_server_init.md) | Is an alias for mysql\_library\_init in MariaDB Connector/C, used to initialize the client library before making any other calls. | | [`mysql_session_track_get_first()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_session_track_get_first.md) | Retrieves the first session state change notification from the server, covering schema changes, system variables, and state flags. Added in Connector/C 3.0. | | [`mysql_session_track_get_next()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_session_track_get_next.md) | Retrieves subsequent session state change notifications after mysql\_session\_track\_get\_first, called repeatedly until a nonzero value signals end of data. | | [`mysql_set_character_set()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_set_character_set.md) | Sets the default character set for a MariaDB Connector/C connection, ensuring mysql\_real\_escape\_string uses the correct encoding. | | [`mysql_set_server_option()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_set_server_option.md) | Enables or disables multi-statement support on a MariaDB connection using MYSQL\_OPTION\_MULTI\_STATEMENTS\_ON or \_OFF. | | [`mysql_set_local_infile_handler()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_set_local_infile_handler.md) | Registers custom callback functions for init, read, end, and error phases of a LOAD DATA LOCAL INFILE operation in MariaDB Connector/C. | | [`mysql_set_local_infile_default()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_set_local_infile_default.md) | Resets local infile callbacks to the Connector/C internal defaults, reversing any custom handler registered via mysql\_set\_local\_infile\_handler. | | [`mysql_shutdown()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_shutdown.md) | Sends a shutdown request to the MariaDB server over the current connection, requiring the SHUTDOWN privilege for the authenticated user. | | [`mysql_sqlstate()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_sqlstate.md) | Returns the five-character SQLSTATE error code for the most recent MariaDB Connector/C function call, with 00000 indicating success. | | [`mysql_ssl_set()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_ssl_set.md) | Configures TLS parameters including key, certificate, CA, and cipher list for a MariaDB connection, and must be called before mysql\_real\_connect. | | [`mysql_stat()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_stat.md) | Returns a status string from the MariaDB server covering uptime, active threads, query count, open tables, and queries per second. | | [`mysql_store_result()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_store_result.md) | Retrieves a complete buffered result set from the last executed MariaDB query, returning NULL on error or for non-SELECT statements. | | [`mysql_thread_end()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_thread_end.md) | Releases thread-local memory allocated by mysql\_thread\_init and must be called explicitly before a thread exits to avoid memory leaks. Deprecated in Connector/C 3.0. | | [`mysql_thread_id()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_thread_id.md) | Retrieves the thread identifier for an active connection; the value may change after a reconnect if the reconnect option is enabled. | | [`mysql_thread_init()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_thread_init.md) | Initializes thread-local variables for multi-threaded Connector/C clients; called automatically by mysql\_init if not invoked explicitly. Deprecated in Connector/C 3.0. | | [`mysql_thread_safe()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_thread_safe.md) | Returns 1 if the MariaDB Connector/C client library was compiled with thread-safety support, or zero otherwise. | | [`mysql_use_result()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_use_result.md) | Initiates unbuffered retrieval of a query result set row by row from the MariaDB server, blocking the connection until all rows are fetched or freed. | | [`mysql_warning_count()`](/docs/connectors/mariadb-connector-c/api-functions/mysql_warning_count.md) | Retrieves the warning count from the most recent query execution; use SHOW WARNINGS for the full warning message text. |