多线程连接MySql

来源：互联网发布：lil pump 知乎编辑：程序博客网时间：2024/05/29 21:17

（一）前置条件：

（1） Linux 已经安装好 mysql 数据库；

（2） Linux 已经安装了 gcc 编译器；

（二）数据库准备：

为了便于描述，假设数据库的 root 用户密码为 root。

（1）以 root 用户登陆数据库

#mysql -u root –p

mysql>

（2）创建数据 testdb

mysql> create database testdb;

（3）创建表

mysql> use testdb;

mysql> create table user_info ('user_id" NOT NULL,

'usr_name NOT NULL,

PRIMARY KEY ('user_id')）；

（4）向表中插入一条记录

mysql> insert into usr_info(user_id, user_name) values(1, 'abc');

Source Code:

#include <stdio.h>
#include <string>
#include <mysql.h>
#include <pthread.h>

using namespace std;

struct SqlStr
{
MYSQL* mpMysql;
string mStr;
};

void* RunSql(void* ipStr)
{
int hr = 0;
SqlStr* lpSqlStr = (SqlStr *)ipStr;

if (mysql_real_query(lpSqlStr->mpMysql, lpSqlStr->mStr.c_str(), (unsigned int)lpSqlStr->mStr.length()) == 0)
{
    printf("query successful\n");
}
else
{
    printf("query failed\n");
    hr = -1;
}

return NULL;
}

void* DisplayTable(void* ipMysql)
{
int hr = 0;
int t;
MYSQL* lpMysql = (MYSQL *)(ipMysql);

string query("select * from user_info;");
    if(mysql_real_query(lpMysql, query.c_str(),(unsigned int)query.length())==0){
          printf("query successful\n");
    }else{
          printf("query failed\n");
          hr = -1;
    }

MYSQL_RES* res=mysql_store_result(lpMysql);
MYSQL_ROW row;

   while(row=mysql_fetch_row(res))
{
    for(t=0;t<mysql_num_fields(res);t++)
    {
       printf("%s\t",row[t]);
    }
    printf("\n");
}

return NULL ;
}

int main()
{
   MYSQL mysql;
   //char *query;
   int t;
   mysql_init(&mysql);
/*connection*/
    if(!mysql_real_connect(&mysql,"localhost","root","root","dengzhi",0,NULL,0)){
          printf("Connect failed\n");
          return -1;
    }else{
          printf("Connect successful\n");
    }

   pthread_t ltDispThread;
   if ( pthread_create(&ltDispThread, NULL, DisplayTable, &mysql) )
     printf("Create thread error\n");

if ( pthread_join(ltDispThread, NULL) )
{
    printf("error joining thread.\n");
    return -1;
}

SqlStr lStr1;
lStr1.mpMysql = &mysql;
lStr1.mStr = string("insert into user_info values (2, 'def')");

pthread_t ltInsertThread;
   if ( pthread_create(&ltInsertThread, NULL, RunSql, &lStr1) )
     printf("Create thread error\n");

if ( pthread_join(ltInsertThread, NULL) )
{
printf("error joining thread.\n");
return -1;
}

mysql_free_result(res);
mysql_close(&mysql);
return 0;
}

编译：

gcc -o sqlconnect -g sqlconnect.c -I/usr/include/mysql -L/usr/lib64/mysql -lmysqlclient

调试： gdb ./sqlconnect

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