public string ExecuteScalar(string sql)
{
string result = "";
switch (_dbConn.DbType)
{
case EDbType.MySql:
object resultObj=new MySqlCommand(sql, mySqlConn).ExecuteScalar();
result = resultObj ==null?"":resultObj.ToString();
break;
case EDbType.Oracle:
object oracleResultObj = new OracleCommand(sql, oracleConn).ExecuteScalar();
result = oracleResultObj == null ? "" : oracleResultObj.ToString();
break;
}
return result;
}