mysql C API statment and bind 执行查询

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本文介绍了一个使用 C++ 进行 MySQL 数据库操作的示例程序，展示了如何通过预编译语句进行数据查询及插入操作。该示例包括了数据库连接、SQL 语句准备与执行等关键步骤。

#include <string>
#include <mysql/mysql.h>
#include <default.h>

typedef std::string string;

struct mysql_parm{
string host;
string user;
string password;
string database;
string unixsock;
};
class DBSTMT;
class DBMysql;

class DBSTMT{
DBSTMT(const DBSTMT&);
DBSTMT& operator=(const DBSTMT&);
MYSQL_STMT* stmt_;
public:
DBSTMT(pcsz_t query,DBMysql& mysql);
void execute(){
  if(mysql_stmt_execute(stmt_))
   throw mysql_stmt_error(stmt_);
}

void execute(MYSQL_BIND* bind){
  if(mysql_stmt_execute(stmt_))
   throw mysql_stmt_error(stmt_);
  if(mysql_stmt_bind_result(stmt_,bind)){
   throw mysql_stmt_error(stmt_);
  }
  if(mysql_stmt_store_result(stmt_))
   throw mysql_stmt_error(stmt_);
}

//void execute(){
// if(mysql_stmt_execute(stmt_))
//  throw mysql_stmt_error(stmt_);
//}

void bind(MYSQL_BIND* bind){
  if(mysql_stmt_bind_param(stmt_,bind) )
   throw mysql_stmt_error(stmt_);
}

int fetch(){
  return mysql_stmt_fetch(stmt_)==0;
}
~DBSTMT(){
  if(stmt_){
   mysql_stmt_close(stmt_);
  }
}

};

class DBMysql{
DBMysql(const DBMysql&);
DBMysql&operator=(const DBMysql&);
MYSQL * mysqlPtr_;

uint32_t errno_;
protected:
friend class DBSTMT;
MYSQL_STMT* _createSTMT(){
  MYSQL_STMT *ret=mysql_stmt_init(mysqlPtr_);
  if(ret)
   return ret;
  errno_=mysql_errno(mysqlPtr_);
  throw mysql_error(mysqlPtr_);
}
public:
const char* strerr(){
  return mysql_error(mysqlPtr_);
}
DBMysql():mysqlPtr_(NULL){
  mysqlPtr_=mysql_init(NULL);
  if(NULL== mysqlPtr_)
   throw "Mysql :outof memory";
}
void open(const mysql_parm& parm){
  if(!mysql_real_connect(mysqlPtr_,
   parm.host.c_str(),
   parm.user.c_str(),
   parm.password.c_str(),
   parm.database.c_str(),
   0,
   parm.unixsock.c_str(),
   0 ))
  {
   errno_=mysql_errno(mysqlPtr_);
   throw(mysql_error(mysqlPtr_));
  }
}

void close(){
  if(mysqlPtr_)
  {
   mysql_close(mysqlPtr_);
   mysqlPtr_=NULL;
  }
}

};

DBSTMT::DBSTMT(pcsz_t query,DBMysql& mysql):stmt_(NULL){
stmt_=mysql._createSTMT();
if(!stmt_)
  throw mysql.strerr();
if( mysql_stmt_prepare(stmt_,query,strlen(query)) )
{
  //const char* err=

  throw mysql_stmt_error(stmt_);
}

}

struct account{
char user[36];
byte password[16];
uint32_t status;
uint32_t id;
};

#define DECL_BIND(h,n)/
class bind_##h:public h{/
typedef h parent;/
MYSQL_BIND  _bind[n];/
my_bool   _is_null[n];/
unsigned long _length[n];/
public:/
bind_##h(){/
  int i=0;/
  bzero(_bind,sizeof(_bind));

#define BIND_BIN(x,l)/
_bind[i].buffer_type= MYSQL_TYPE_STRING;/
_bind[i].buffer= (char *)&(parent::x);/
_bind[i].buffer_length= l;/
_bind[i].is_null= _is_null+i;/
_bind[i].length= _length+i;/
++i;

#define BIND_INT(x)/
_bind[i].buffer_type= MYSQL_TYPE_LONG;/
_bind[i].buffer= (char *)&(parent::x);/
_bind[i].buffer_length= 0;/
_bind[i].is_null= _is_null+i;/
_bind[i].length= _length+i;/
++i;

#define END_BIND(h) }/
operator MYSQL_BIND*(){/
return _bind;/
}/
};

//account acc;
//
//DECL_BIND(4)
// BIND_BIN(acc.user,32);
// BIND_BIN(acc.password,16);
// BIND_INT(acc.status);
// BIND_INT(acc.id);

// smt.executeAndStore(bind);
//END_BIND(4)

DECL_BIND(account,4)
BIND_BIN(user,32)
BIND_BIN(password,16)
BIND_INT(status)
BIND_INT(id)
END_BIND(account)

int main(){

try{

  DBMysql mysql;
  mysql_parm parm;
  parm.host="localhost";
  parm.user="root";
  parm.password="mypwd";
  parm.unixsock="/var/lib/mysql/mysql.sock";
  parm.database="testdb";
  mysql.open(parm);

  DBSTMT smt("select user,password,status,id from account",mysql);
  DBSTMT smt1("insert into account(user,password,status) value(?,?,?)",mysql);
//

  bind_account acc;

  smt.execute(acc);

  while(smt.fetch()){
   //acc.user[length[0]]=0;
   //acc.user,
   printf("%s %d %d/n",acc.user,acc.status,acc.id);
   //printf("%d %d/n",acc.status,acc.id);

   ;

  };
  smt1.bind(acc);
  smt1.execute();



}catch(const char* err){
  printf("error:%s/n",err);
}

return 0;

}