float类型的数据为什么不能存入数据库？

Question

function AddNew($TableName="")  //标志开始添加数据
    {
        $this->Connect();
              $this->Initialize();
              if(!empty($TableName))
                $this->sTName=strtolower($TableName);
              if($this->NewEdit>0)
              {
                $this->nErr=1;
                $this->sErr="AddNew:你正在对数据库进行添加或更新操作！";
                return;
              }
              if(empty($this->sTName))
              {
                $this->nErr=1;
                $this->sErr="AddNew:想要添加的数据库表为空，可以在构造时指定，也可在AddNew()时指定！";
                return;
              }
              unset($this->aNew);
              $this->aNew=array();
              $this->NewEdit=1;
              $strSQL="select * from ".$this->sTName;
                  $this->sSQL=$strSQL;
              if(!$this->nResult=mysql_query($strSQL))
              {
                $this->nErr=1;
                $this->sErr="AddNew:SQL语句：".strSQL."<br><br>MySql错误：".mysql_error();
                return;
              }
              $this->nCols=mysql_num_fields($this->nResult);
              unset($this->aFName);
              $this->aFName=array();
              for($i=0;$i<$this->nCols;$i++)
                $this->aFName[$i]=strtolower(mysql_field_name($this->nResult,$i));
    }

Answer 1

请各位帮帮忙！这个问题怎么解决，我把该字段改为int型就可以插入数据了，可是为什么float类型就不能插入数据呢？