db_mysql.cpp

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#include "db_mysql.h"
 
db_mysql::db_mysql()
    :m_Mysql(NULL)
    ,m_Res(NULL)
    ,m_bConnect(false)
    ,m_bSelectDB(false)
    ,m_bExecute(false)
    ,m_bGetRow(false)
    ,m_bInit(false)
{
    ;   
}
db_mysql::db_mysql(string host,string user,string passwd,string db)
    :m_Mysql(NULL)
    ,m_Res(NULL)
    ,m_bConnect(false)
    ,m_bSelectDB(false)
    ,m_bExecute(false)
    ,m_bGetRow(false)
{
    Init(host,user,passwd,db);
}   
 
void db_mysql::Init(string host,string user,string passwd,string db)
{
    m_strHost = host;
    m_strUser = user;
    m_strPasswd = passwd;
    m_strDB = db;
    m_bInit = true;
    if(!db.empty())
    {
        m_bSelectDB = true;
    }
}
void db_mysql::SetQuery(string query)
{
    m_strQuery=query;
}
bool db_mysql::Connect(void)
{
    if(!m_bConnect)
    {
        my_bool b = 0;
        if(!(m_Mysql=mysql_init(NULL)))
            {
            cout<<"Init mysql error!!"<<endl;
            return false; 
            }
//      mysql_options(m_Mysql,MYSQL_REPORT_DATA_TRUNCATION,&b);
            if(!mysql_real_connect(m_Mysql,m_strHost.c_str(),m_strUser.c_str(),m_strPasswd.c_str(),m_strDB.c_str(),0,NULL,0))
        {
            cout<<"Connect error!!"<<endl;
            mysql_close(m_Mysql);
            return false;
        }
    }
    else
    {
        cout<<"You are reconnecting!"<<endl;
        return false;   
    }
    m_bConnect = true;
    return true;
}
bool db_mysql::SelectDB(string db)
{
    if(!m_bConnect)
    {
        cout<<"You must connect before select db!";
        return false;
    }
    if(mysql_select_db(m_Mysql,db.c_str()))
    {
        cout<<"Select database error!"<<endl;
        return false;
    }
    m_strDB = db;
    m_bSelectDB = true;
    return true;
}
    
bool db_mysql::Execute(string query)
{
    if((!m_bConnect)||(!m_bSelectDB))
    {
        cout<<"You executing query before connection or select db!"<<endl;
        return false;
    }
    if(!query.empty())
    {
        m_strQuery=query;
    }
    if(m_strQuery.empty())
    {
        cout<<"Your haven't set query string!"<<endl;
        return false;   
    }
    else
    {
        Free_Result();
        if(mysql_real_query(m_Mysql,m_strQuery.c_str(),m_strQuery.size()))
        {
            cout<<"Execute query error!"<<endl;
            return false;   
        }   
    }
//zhaohs
        Field_num=mysql_field_count(m_Mysql);
        if(Field_num==0){
    m_result=false;
    }
    else {m_result=true;}
//zhaohs
    m_Res = mysql_store_result(m_Mysql);
    m_bExecute = true;
    return true;
}
    
bool db_mysql::GetRow(my_ulonglong row)
{
    if(!m_bExecute)
    {
        cout<<"You must execute query before get row!"<<endl;
        return false;
    }
    if(row!=NEXT_ROW)
    {
        if(row>=mysql_num_rows(m_Res)||row<0)
        {
//          cout<<"Select row error! Row number must be set in range!"<<endl;
            return false;
        }
        mysql_data_seek(m_Res,row); 
    }
    m_Row=mysql_fetch_row(m_Res);
    if(m_Row==NULL)
    {
        cout<<"fetch_row error!"<<endl; 
        return false;
    }
    
    m_bGetRow = true;
    return true;
}
 
string db_mysql::GetField(unsigned int n)
{
        
    if(!m_bGetRow)
    {
        cout<<"You must get a row before getfield value!"<<endl;
        return "";
    }
    if(m_Row[n]!=NULL){ return (string)m_Row[n];}
    else return "";
}
//// gaizao
/*string db_mysql::GetField(string name)
{
 
         if(!m_bGetRow)
             {cout<<"You must get a row before getfield value!"<<endl;
          return "";
         }
        if(m_Row[name]!=NULL){ return (string)m_Row[name];}
        else return "";
}*/
/////  myself---zhaohs
string db_mysql::GetField_name(unsigned int n)
{
        if(!m_result)
            {
         cout<<"error:no select!"<<endl;
        return "";
        }
        m_field = mysql_fetch_field_direct(m_Res, n);
    return string(m_field->name);
 
 
//  num_fields = mysql_num_fields(result);
//  m_field = mysql_fetch_fields(m_Res);
  //      std::cout<<m_field[n].name<<std::endl;
//  return m_field[n].name;
 
       
}
 
////
unsigned long db_mysql::Num_Rows(void)
{
    if(!m_bExecute)
    {
        cout<<"You are get number of rows before execute!"<<endl;
        return 0;
    }
    return mysql_num_rows(m_Res);
}
 
void db_mysql::Free_Result(void)
{
    if(m_bExecute)
    {
        mysql_free_result(m_Res);
        m_bExecute = false;
        m_bGetRow = false;  
    }
}
 
void db_mysql::Close(void)
{
    if(m_bConnect)
    {
        Free_Result();
        mysql_close(m_Mysql);
        m_bConnect = false;
    }
}
 
db_mysql::~db_mysql()
{
    Free_Result();
    Close();
}