[置顶] Linux C连接Mysql数据库

1. 连接数据库

 /*练习mysql数据库的连接*/
 #include <stdio.h>
 #include <mysql.h>

 int main()
 {
     MYSQL mysql;
     int t, r;
     /*连接之前，先用mysql_init初始化MYSQL连接句柄*/
     mysql_init(&mysql);
     /*使用mysql_real_connect连接服务器,其参数依次为MYSQL句柄，服务器IP地址，
     登录mysql的用户名，密码，要连接的数据库等*/
     if(!mysql_real_connect(&mysql, "localhost", "root", "6748355", "spytest", 0, NULL, 0)) {
         printf("Error connecting to Mysql!\n");
     }else {
         printf("Connected Mysql successful!\n");
     }
     /*关闭连接*/
     mysql_close(&mysql);
     return 0;
 }

2. 数据库查询

 /*练习mysql数据库的查询*/
 #include <stdio.h>
 #include <string.h>
 #include "mysql.h"


 int main()
 {
     MYSQL mysql;
     MYSQL_RES *res;
     MYSQL_ROW row;
     char *query;
     int flag, t;
     mysql_init(&mysql);
     if(!mysql_real_connect(&mysql, "localhost", "root", "6748355", "spytest", 0, NULL, 0)) {
         printf("Failed to connect to Mysql!\n");
         return 0;
     }else {
         printf("Connected to Mysql successfully!\n");
     }
     query = "select * from log";
     /*查询，成功则返回0*/
     flag = mysql_real_query(&mysql, query, (unsigned int)strlen(query));
     if(flag) {
         printf("Query failed!\n");
         return 0;
     }else {
         printf("[%s] made...\n", query);
     }


     /*mysql_store_result讲全部的查询结果读取到客户端*/
     res = mysql_store_result(&mysql);
     /*mysql_fetch_row检索结果集的下一行*/
     while(row = mysql_fetch_row(res)) {
         /*mysql_num_fields返回结果集中的字段数目*/
         for(t=0; t<mysql_num_fields(res); t++)
         {
             printf("%s\t", row[t]);
         }
         printf("\n");
     }
     mysql_close(&mysql);
     return 0;
 }

3. 数据库插入数据

 /*练习mysql数据库的数据添加*/
 #include <stdio.h>
 #include <string.h>
 #include "mysql.h"


 int main()
 {
     MYSQL mysql;
     MYSQL_RES *res;
     MYSQL_ROW row;
     char *query;
     int flag, t;
     mysql_init(&mysql);
     if(!mysql_real_connect(&mysql, "localhost", "root", "6748355", "spytest", 0, NULL, 0)) {
         printf("Failed to connect to Mysql!\n");
         return 0;
     }else {
         printf("Connected to Mysql successfully!\n");
     }
     query = "insert into log(title, keyword, content) values('sleep', 'rest', 'I have a dream')";
     /*插入，成功则返回0*/
     flag = mysql_real_query(&mysql, query, (unsigned int)strlen(query));
     if(flag) {
         printf("Insert data failure!\n");
         return 0;
     }else {
         printf("Insert data success!\n");
     }


     mysql_close(&mysql);
     return 0;
 }

4. 数据库删除

 /*练习mysql数据库的删除*/
 #include <stdio.h>
 #include <string.h>
 #include "mysql.h"

 int main()
 {
     MYSQL mysql;
     MYSQL_RES *res;
     MYSQL_ROW row;
     char *query;
     int flag, t;
     mysql_init(&mysql);
     if(!mysql_real_connect(&mysql, "localhost", "root", "6748355", "spytest", 0, NULL, 0)) {
         printf("Failed to connect to Mysql!\n");
         return 0;
     }else {
         printf("Connected to Mysql successfully!\n");
     }
     query = "delete from log where log_id=3";
     /*删除，成功则返回0*/
     flag = mysql_real_query(&mysql, query, (unsigned int)strlen(query));
     if(flag) {
         printf("Delete data failure!\n");
         return 0;
     }else {
         printf("Delete data success!\n");
     }

     mysql_close(&mysql);
     return 0;
 }