Mysql 一次性执行多条语句的实现

1.mysql数据库默认情况下，mysql_query()是一次只执行一条语句。

#include "stdafx.h"
#include <mysql.h>
#include <string>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
MYSQL mysql;
mysql_init(&mysql);

MYSQL* pConn = mysql_real_connect(&mysql,"127.0.0.1","root","root","test",3306,NULL,0);

if(pConn == NULL){
printf("connect db error!\n");
int n = mysql_errno(&mysql);
string strError = mysql_error(&mysql);

printf("error id: %d ,%s",n,strError.c_str());

return 1;
}

string s = "";
string sql = "";

s = "insert into t1 values(2,'ya');";

//执行多条语句
/*for(int i = 0; i < 10;i++){
sql+=s;
}*/
//执行一条语句
sql = s;

int err = mysql_query(&mysql,sql.c_str());
if(err!=0){
printf("execute sql failed.\n");
}

mysql_close(&mysql);
mysql_library_end();

getchar();

return 0;
}

默认情况下一次执行一条语句的结果输出如下：



一次执行多条语句的结果输出如下：



2.为了实现mysql_query一次可以执行多条语句：

有两个方法：

a)在建立数据库连接时指定

//a)连接时指定
MYSQL* pConn = mysql_real_connect(&mysql,"127.0.0.1","root","root","test",3306,NULL,CLIENT_MULTI_STATEMENTS);

b)要执行多条语句之前指定

MYSQL* pConn = mysql_real_connect(&mysql,"127.0.0.1","root","root","test",3306,NULL,0);
......
//连接时关闭，执行多条语句之前指定
mysql_set_server_option(&mysql,MYSQL_OPTION_MULTI_STATEMENTS_ON);
int err = mysql_query(&mysql,sql.c_str());
mysql_set_server_option(&mysql,MYSQL_OPTION_MULTI_STATEMENTS_ON);

3.完整代码：

#include "stdafx.h"
#include <mysql.h>
#include <string>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
MYSQL mysql;
mysql_init(&mysql);

MYSQL* pConn = mysql_real_connect(&mysql,"127.0.0.1","root","root","test",3306,NULL,0);
//a)连接时指定
//MYSQL* pConn = mysql_real_connect(&mysql,"127.0.0.1","root","root","test",3306,NULL,CLIENT_MULTI_STATEMENTS);

if(pConn == NULL){
printf("connect db error!\n");
int n = mysql_errno(&mysql);
string strError = mysql_error(&mysql);

printf("error id: %d ,%s",n,strError.c_str());

return 1;
}

string s = "";
string sql = "";

s = "insert into t1 values(2,'ya');";

//执行多条语句
for(int i = 0; i < 10;i++){
sql+=s;
}
//执行一条语句
//sql = s;

//连接时关闭，执行多条语句之前指定
mysql_set_server_option(&mysql,MYSQL_OPTION_MULTI_STATEMENTS_ON);
int err = mysql_query(&mysql,sql.c_str());
mysql_set_server_option(&mysql,MYSQL_OPTION_MULTI_STATEMENTS_ON);
if(err!=0){
printf("execute sql failed.\n");
}else{
printf("execute sql successed.\n");
}

mysql_close(&mysql);
mysql_library_end();

getchar();

return 0;
}