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  • 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)
    
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  • 原文地址:https://www.cnblogs.com/zhangxuechao/p/11709885.html
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