MariaDB Connector/C Data structures
Contents
This chapter describes the public data structures used by MariaDB Connector/C
MYSQL
The MYSQL
structure represents one database connection and is used by most of MariaDB Connector/C's API functions. The MYSQL structure needs to be allocated and initialized by mysql_init() API function.
The MYSQL
structure should be considered as opaque, copying or changing values of it's members might end up in unexpected results, errors or program crashes.
MYSQL_RES
The MYSQL_RES
structure represents a result set which contains data and meta data information. It will be returned by mysql_use_result(), mysql_store_result() and mysql_stmt_result_metadata() API functions and needs to be released by mysql_free_result().
The MYSQL_RES
structure should be considered as opaque, copying or changing values of it's members might end up in unexpected results, errors or program crashes.
MYSQL_STMT
The MYSQL_STMT
structure represents a prepared statement handle and is used by MariaDB Connector/C's prepared statemnt API functions. The MYSQL_STMT structure needs to be allocated and initialized by mysql_stmt_init() API function.
The MYSQL_STMT
structure should be considered as opaque, copying or changing values of it's members might end up in unexpected results, errors or program crashes.
MYSQL_FIELD
The MYSQL_FIELD
structure describes the meta data of a column. It has the following members:
char * | name | The name of the column |
unsigned int | name_length | The length of column name |
char * | org_name | The original name of the column |
unsigned int | org_name_length | The length of original column name |
char * | table | The name of the table |
unsigned int | table_length | The length of table name |
char * | org_table | The original name of the table |
unsigned int | org_table_length | The length of original table name |
char * | db | The name of the database (schema) |
unsigned int | db_length | The length of database name |
char * | catalog | The catalog name (always 'def' ) |
unsigned int | catalog_length | The length of catalog name |
char * | def | default value |
unsigned int | def_length | The length of default value |
unsigned int | length | The length (width) of the column definition |
unsigned int | max_length | The maximum length of the column value |
unsigned int | flags | Flags |
unsigned int | decinals | Number of decimals |
enum enum_field_types | type | Field type |
MYSQL_BIND
The MYSQL_BIND
structure is used to provide parameters for prepared statement or to receive output column value from a prepared statement.
unsigned long * | length | Pointer for the length of the buffer (not used for parameters) |
my_bool * | is_nulll | Pointer which indicates if column is NULL (not used for parameters) |
my_bool * | error | Pointer which indicates if an error occured |
void * | buffer | Data buffer which contains or receives data |
char * | u.indicator | Array of indicator variables for bulk operation parameter |
unsigned long | buffer_length | Length of buffer |
enum enum_field_types | buffer_type | Buffer type |
unsigned long | length_value | Used if length pointer is NULL |
my_bool | error_value | Used if error pointer is NULL |
my_bool | is_null_value | Used if is_null pointer is NULL |
my_bool | is_unsigned | Set if integer type is unsigned |
my_bool | is_null_value | Used if value is NULL |