linux mysql连接

1. 添加头文件

# apt-get install libmysqlclient-dev

引入头文件

#include <mysql/mysql.h>

2. 举例

MYSQL *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 client_flag)

int mysql_real_query(MYSQL *mysql, const char *query, unsigned int length)

int main()
{
   MYSQL mysql;
   MYSQL_RES *res;
   MYSQL_ROW row;

   char sql[50] = {0};
   int t;
   sprintf(sql, "select * from user");

   mysql_init(&mysql);     //初始化mysql结构

   //if(mysql_real_connect(&mysql, NULL, "root", "123456", "mysql", 3306, NULL, 0))
   if(mysql_real_connect(&mysql, "127.0.0.1", "root", "123456", "mysql", 0, NULL, 0))
   {
      printf("连接数据库成功！
");
   }
   else
   {
      printf("连接数据库失败：%s
", mysql_error(&mysql));
   }

   t = mysql_real_query(&mysql, sql, (unsigned int)strlen(sql));   //在服务器上执行定义的sql语句

   if(t)
   {
      printf("查询语句错误：%s
", mysql_error(&mysql));
   }
   else
   {
      res = mysql_store_result(&mysql);       //读取结果置于结构中

      while(row = mysql_fetch_row(res))       //检索结果集的下一行
      {
         unsigned long *lengths;
         lengths = mysql_fetch_lengths(res);    //当前行列的长度

         for(t = 0; t < mysql_num_fields(res); t++)      //获取结合集中的行数(行内)
         {
            printf("%d ", (int)lengths[t]);
            printf("%s
", row[t] ? row[t] : "NULL"); //防止指针为空报段错误
         }

         printf("
");
      }

      mysql_free_result(res);
   }

   printf("释放结果集的空间...
");
   mysql_close(&mysql);    //释放数据库

   return 0;
}

需要链接库：libmysqlclient.so

3. 结果集中的行数

mysql_field_count(MYSQL *mysql)