c语言mysql_query mysqlc语言结构体

导读:MySQL是一种关系型数据库管理系统,C语言是一种通用的高级计算机编程语言 。在使用MySQL时,我们可以通过C语言中的结构体来进行操作 。本文将介绍MySQL C语言结构体的相关知识 。
1. MYSQL结构体
MYSQL结构体是MySQL C API中最重要的结构体之一,它包含了连接到MySQL服务器所需的所有信息 。以下是MYSQL结构体的定义:
typedef struct st_mysql {
NET net;
void *unused_1;
char *host,*user,*passwd,*unix_socket,*server_version,*host_info,
*info,*db;
unsigned int port,client_flag,server_capabilities;
unsigned int protocol_version;
unsigned int field_count;
unsigned int thread_id;
unsigned long affected_rows;
unsigned long insert_id;
unsigned long extra_info;
unsigned long packet_length;
my_bool status;
my_bool free_me;
my_bool reconnect;
my_bool unused_2;
unsigned int options;
enum mysql_option methods_to_use;
my_bool unused_3;
char *stmt_charset;
【c语言mysql_query mysqlc语言结构体】char *charset_name;
MYSQL_FIELD *fields;
MEM_ROOT field_alloc;
MYSQL_DATA *result;
my_ulonglong row_offset;
MYSQL_ROW row;
MYSQL_ROW current_row;
unsigned long *lengths;
MYSQL_BIND *parameters;
MEM_ROOT param_alloc;
MYSQL_STMT *stmts;
my_bool *unbuffered_fetch_owner;
char *info_buffer;
struct st_mysql_options *options_mysql;
my_bool *more_results;
my_bool *multi_stmts;
my_bool *free_multi_results;
unsigned int *stmt_id;
MYSQL_RES **multi_res_info;
unsigned int *result_array_size;
unsigned int *result_current_pos;
my_bool **bind_result_is_null;
my_bool *unused_4;
void *extension;
} MYSQL;
2. MYSQL_RES结构体
MYSQL_RES结构体是用于存储查询结果的结构体 , 它包含了查询结果集中的所有行和列 。以下是MYSQL_RES结构体的定义:
typedef struct st_mysql_res {
my_ulonglong row_count;
unsigned int field_count, current_field;
MYSQL_FIELD *fields;
MYSQL_DATA *data;
MYSQL_ROWS *data_cursor;
MEM_ROOT field_alloc;
MYSQL_ROW row;
MYSQL_ROW current_row;
unsigned long *lengths;
MYSQL *handle;
my_bool eof;
} MYSQL_RES;
3. MYSQL_ROW结构体
MYSQL_ROW结构体是一维数组,用于存储查询结果集中的一行数据 。以下是MYSQL_ROW结构体的定义:
typedef char **MYSQL_ROW;
4. MYSQL_FIELD结构体
MYSQL_FIELD结构体是用于存储查询结果集中的列信息的结构体 。以下是MYSQL_FIELD结构体的定义:
typedef struct st_mysql_field {
char *name; /* Name of column */
char *org_name; /* Original column name, if an alias */
char *table; /* Table of column if column was a field */
char *org_table; /* Org table name, if table was an alias */
char *db; /* Database for table */
char *catalog; /* Catalog for table */
char *def; /* Default value (set by mysql_list_fields) */
unsigned long length; /* Width of column */
unsigned long max_length; /* Max width for selected set */
unsigned int name_length;
unsigned int org_name_length;
unsigned int table_length;
unsigned int org_table_length;
unsigned int db_length;
unsigned int catalog_length;
unsigned int def_length;
unsigned int flags; /* Div flags */
unsigned int decimals; /* Number of decimals in field */
unsigned int charsetnr; /* Character set */
enum enum_field_types type; /* Type of field. See mysql_com.h for types */
void *extension;
} MYSQL_FIELD;
总结:本文介绍了MySQL C语言结构体的相关知识,包括MYSQL结构体、MYSQL_RES结构体、MYSQL_ROW结构体和MYSQL_FIELD结构体 。通过使用这些结构体,我们可以方便地进行MySQL数据库的操作 。

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