PHP新手用的Insert和Update语句构造类

　　$mysql = new sqlstr("table1");

　　$mysql->set("name","value");

　　$mysql->set("name","1",true);

　　echo $mysql->insertSql();

　　class sqlstr

　　{

　　private $param=array();

　　private $tablename;

　　function sqlstr($tablename)

　　{

　　$this->tablename = $tablename;

　　}

　　public function set($name,$value,$isnum=false){

　　$value = str_replace("'","''",$value);

　　$this->param[$name]=array($value,$isnum);

　　}

　　public function insertSql(){

　　$keys="";

　　$values="";

　　foreach($this->param as $key =>$value){

　　$keys = $keys . $key . ",";

　　if($value[1]){

　　$values = $values . $value[0] . ",";

　　}else{

　　$values = $values . "'" . $value[0] . "',";

　　}

　　}

　　if($keys!=""){$keys=substr($keys,0,strlen($keys)-1) ;}

　　if($values!=""){$values=substr($values,0,strlen($values)-1) ;}

　　return "insert into " .$this->tablename ."($keys) values($values)";

　　}

　　public function updateSql($cond){

　　$group="";

　　foreach($this->param as $key =>$value){

　　$group .= $key . "=";

　　if($value[1]){

　　$group.= $value[0] . ",";

　　}else{

　　$group.= "'" . $value[0] . "',";

　　}

　　}

　　if($group!=""){$group=substr($group,0,strlen($group)-1) ;}

　　return "update " . $this->tablename ." set $group where " . $cond;

　　}

　　}