C 언어 Mysql 함수 조작

데이터 유형

MYSQL ， ， 


 typedef struct st_mysql
 {
   NET           net;                    /* Communication parameters */
   unsigned char *connector_fd;          /* ConnectorFd for SSL */
   char          *host,*user,*passwd,*unix_socket,*server_version,*host_info;
   char          *info, *db;
   struct charset_info_st *charset;
   MYSQL_FIELD   *fields;
   MEM_ROOT      field_alloc;
   my_ulonglong affected_rows;
   my_ulonglong insert_id;               /* id if insert on table with NEXTNR */
   my_ulonglong extra_info;              /* Not used */
   unsigned long thread_id;              /* Id for connection in server */
   unsigned long packet_length;
   unsigned int  port;
   unsigned long client_flag,server_capabilities;
   unsigned int  protocol_version;
   unsigned int  field_count;
   unsigned int  server_status;
   unsigned int  server_language;
   unsigned int  warning_count;
   struct st_mysql_options options;
   enum mysql_status status;
   my_bool       free_me;                /* If free in mysql_close */
   my_bool       reconnect;              /* set to 1 if automatic reconnect */

   /* session-wide random string */
   char          scramble[SCRAMBLE_LENGTH+1];

 /*
   Set if this is the original connection, not a master or a slave we have
   added though mysql_rpl_probe() or mysql_set_master()/ mysql_add_slave()
 */
   my_bool rpl_pivot;
   /*
     Pointers to the master, and the next slave connections, points to
     itself if lone connection.
   */
   struct st_mysql* master, *next_slave;

   struct st_mysql* last_used_slave; /* needed for round-robin slave pick */
 /* needed for send/read/store/use result to work correctly with replication */
   struct st_mysql* last_used_con;

   LIST  *stmts;                     /* list of all statements */
   const struct st_mysql_methods *methods;
   void *thd;
   /*
     Points to boolean flag in MYSQL_RES  or MYSQL_STMT. We set this flag
     from mysql_stmt_close if close had to cancel result set of this object.
   */
   my_bool *unbuffered_fetch_owner;
   /* needed for embedded server - no net buffer to store the 'info' */
   char *info_buffer;
   void *extension;
 } MYSQL;

데이터베이스 함수

1 mysql_real_connect

MYSQL * STDCALL mysql_real_connect(MYSQL *mysql, const char *host,
const char *user,
const char *passwd,
const char *db,
unsigned int port,
const char *unix_socket,
unsigned long clientflag);

#include   
#include   
    
int main(int argc, const char *argv[])  
{  
    MYSQL   mysql;  
    
    if (NULL == mysql_init(&mysql)) {    // MYSQL   
        printf("mysql_init(): %s
", mysql_error(&mysql));  
        return -1;  
    }  
    
    // MySQL   
    if (NULL == mysql_real_connect(&mysql,  
                "localhost",  
                "root",  
                "shallnet",  
                "db_users",  
                0,  
                NULL,  
                0)) {  
        printf("mysql_real_connect(): %s
", mysql_error(&mysql));  
        return -1;  
    }  
    
    printf("Connected MySQL successful! 
");  
    
    mysql_close(&mysql);  
    return 0;  
}  

2 데이터 조회 문장 함수 mysql_query

int STDCALL mysql_query(MYSQL *mysql, const char *q);

#include 
#include 
#include 
int main(int argc, const char *argv[])
{
    MYSQL           mysql;
    MYSQL_RES       *res = NULL;
    MYSQL_ROW       row;
    char            *query_str = NULL;
    int             rc, i, fields;
    int             rows;
    if (NULL == mysql_init(&mysql)) {
        printf("mysql_init(): %s
", mysql_error(&mysql));
        return -1;
    }
    if (NULL == mysql_real_connect(&mysql,
                "localhost",
                "root",
                "shallnet",
                "db_users",
                0,
                NULL,
                0)) {
        printf("mysql_real_connect(): %s
", mysql_error(&mysql));
        return -1;
    }
    printf("1. Connected MySQL successful! 
");
    query_str = "select * from tb_users";
    rc = mysql_real_query(&mysql, query_str, strlen(query_str));
    if (0 != rc) {
        printf("mysql_real_query(): %s
", mysql_error(&mysql));
        return -1;
    }
    res = mysql_store_result(&mysql);
    if (NULL == res) {
         printf("mysql_restore_result(): %s
", mysql_error(&mysql));
         return -1;
    }
    rows = mysql_num_rows(res);
    printf("The total rows is: %d
", rows);
    fields = mysql_num_fields(res);
    printf("The total fields is: %d
", fields);
    while ((row = mysql_fetch_row(res))) {
        for (i = 0; i < fields; i++) {
            printf("%s\t", row[i]);
        }
        printf("
");
    }
    mysql_close(&mysql);
    return 0;
}

#include 
#include 
#include 
int main(int argc, const char *argv[])
{
    MYSQL           mysql;
    MYSQL_RES       *res = NULL;
    MYSQL_ROW       row;
    char            *query_str = NULL;
    int             rc, i, fields;
    int             rows;
    if (NULL == mysql_init(&mysql)) {
        printf("mysql_init(): %s
", mysql_error(&mysql));
        return -1;
    }
    if (NULL == mysql_real_connect(&mysql,
                "localhost",
                "root",
                "shallnet",
                "db_users",
                0,
                NULL,
                0)) {
        printf("mysql_real_connect(): %s
", mysql_error(&mysql));
        return -1;
    }
    printf("1. Connected MySQL successful! 
");
    query_str = "select * from tb_users";
    rc = mysql_real_query(&mysql, query_str, strlen(query_str));
    if (0 != rc) {
        printf("mysql_real_query(): %s
", mysql_error(&mysql));
        return -1;
    }
    res = mysql_store_result(&mysql);
    if (NULL == res) {
         printf("mysql_restore_result(): %s
", mysql_error(&mysql));
         return -1;
    }
    rows = mysql_num_rows(res);
    printf("The total rows is: %d
", rows);
    fields = mysql_num_fields(res);
    printf("The total fields is: %d
", fields);
    while ((row = mysql_fetch_row(res))) {
        for (i = 0; i < fields; i++) {
            printf("%s\t", row[i]);
        }
        printf("
");
    }
    mysql_close(&mysql);
    return 0;
}

gcc ：gcc ***.c -o *** -lmysqlclient

참고