MYSQL_BIND

MYSQL_BIND}}} structure is used to bind parameters (which will be sent to server) and result sets (output sent from server to client). The {{{MYSQL_BIND}}} structure is bound with [[mysql_stmt_bind_param|mysql_stmt_bind_param()]] or [[mysql_stmt_bind_result|mysql_stmt_bind_result()]] to a prepared statement.

=== Members of MYSQL_BIND structure
* {{{enum enum_field_types}}} **field_type**: Type of the buffer for in- or output. For a complete list of types see section [[types_and_definitions|types and definitions]].
* {{{void}}} **buffer**: Address of a variable, array or structure used for data transfer.
* {{{unsigned long}}} **buffer_length**: Size of buffer in bytes.
* {{{unsigned long *}}} **length**: Pointer to a length variable for output or array of length elements for input (array binding).
* {{{my_bool *}}} **error**: Pointer to an error variable for output.
* {{{my_bool *}}} **is_null**: Ponter to an null indicator for output.
* {{{char *}}} **u.indicator**: Array of indicator variables for input (array binding)
* {{{my_bool}}} **is_unsigned**: set when numeric data type is unsigned

=== Array binding
Array binding for bulk insert/updates was introduced with Connector/C 3.0 and requires MariaDB Server 10.2 or above. It allows client to control the number of rows  that will be physically transferred between the server and the client in one logical bind or fetch. This  can greatly improve the performance of many applications by trading buffer space for time (network traffic) and is a better and more secure alternative to {{{LOAD DATA LOCAL INFILE}}}, especially when the data will be generated within application.

==== Column wise binding
When using column wise binding (default) the application binds up to 3 arrays to a column: A data array, a length array and optional an indicator array.

The number of rows has to be set by calling [[mysql_stmt_attr_set|mysql_stmt_attr_set()]] with option {{{MARIADB_STMT_ARRAY_SIZE

  unsigned int array_size= 100;
  mysql_stmt_attr_set(stmt, MARIADB_STMT_ARRAY_SIZE, array_size);

Each array contains as many elements as specified in array_size parameter.

Row wise binding