Linux 下C语言连接mysql实例详解

sudo apt-get install libmysqlclient-dev

mysql> show databases;+--------------------+| Database      |+--------------------+| information_schema || chat_room     || mysql       || mysql_shiyan    || performance_schema || sys        |+--------------------+6 rows in set (0.00 sec)mysql> use chat_room;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> show tables;+---------------------+| Tables_in_chat_room |+---------------------+| user_message    |+---------------------+1 row in set (0.00 sec)mysql> select * from user_message;+------+-------+--------+| ID  | name | passwd |+------+-------+--------+|  1 | linux | linux ||  2 | lyt  | lyt  |+------+-------+--------+2 rows in set (0.00 sec)

#include<stdio.h>#include<stdlib.h>#include<errno.h>#include<mysql/mysql.h>int main(void){  char *sql;  sql="SELECT * FROM user_message;";  int res;//执行sql语句后的返回标志  MYSQL_RES *res_ptr;//指向查询结果的指针  MYSQL_FIELD *field;//字段结构指针  MYSQL_ROW result_row;//按行返回查询信息  int row,column;//查询返回的行数和列数  MYSQL *conn;//一个数据库链接指针  int i,j;  //初始化连接句柄  conn = mysql_init(NULL);  if(conn == NULL) { //如果返回NULL说明初始化失败    printf("mysql_init failed!/n");    return EXIT_FAILURE;  }  //进行实际连接  //参数　conn连接句柄，host　mysql所在的主机或地址,user用户名,passwd密码,database_name数据库名,后面的都是默认  conn = mysql_real_connect(conn,"localhost","lyt","","chat_room",0,NULL,0);  if (conn) {    printf("Connection success!/n");  } else {    printf("Connection failed!/n");  }  mysql_query(conn,"set names gbk");//防止乱码。设置和数据库的编码一致就不会乱码  res = mysql_query(conn,sql);//正确返回0  if(res) {    perror("my_query");    mysql_close(conn);    exit(0);  } else{    //把查询结果给res_ptr    res_ptr = mysql_store_result(conn);    //如果结果不为空,则输出    if(res_ptr) {      column = mysql_num_fields(res_ptr);      row = mysql_num_rows(res_ptr);      printf("查到%d行/n",row);      //输出结果的字段名      for(i = 0;field = mysql_fetch_field(res_ptr);i++) {        printf("%10s",field->name);      }      puts("");      //按行输出结果      for(i = 1;i < row+1;i++){        result_row = mysql_fetch_row(res_ptr);        for(j = 0;j< column;j++) {          printf("%10s",result_row[j]);        }        puts("");      }    }  }  //退出前关闭连接  mysql_close(conn);  return 0;}

gcc -o mysql a.c -L/usr/lib/mysql -lmysqlclient./mysql Connection success!查到2行    ID   name  passwd     1   linux   linux     2    lyt    lyt