标识对象模式
这个模式主要功能就是创建sql语句中的wehre条件字符串的，下面直接看代码和注释：
namespace woo\mapper;
//字段对象
class Field {
protected $name = null; //字段名称
protected $operator = null; //操作符
protected $comps = array(); //存放条件的数组
protected $incomplete = false; //检查条件数组是否有值
function __construct ($name){
$this->name= $name;
}
//添加where 条件
function addTest($operator,$value){
$this->comps[] = array('name'=>$this->name,'operator'=>$operator,'value'=>$value);
}
//获取存放条件的数组
function getComps(){
return $this->comps;
}
function isIncomplete(){
return empty($this->comps);
}
}
//标识对象
class IdentityObject {
protected $currentfield = null; //当前操作的字段对象
protected $fields = array(); //字段集合
private $and = null;
private $enforce = array(); //限定的合法字段
function __construct($field = null, array $enforce = null){
if(!is_null($enforce)){
$this->enforce = $enforce;
}
if(!is_null($field)){
$this->field($field);
}
}
//获取限定的合法字段
function getObjectFields(){
return $this->enforce;
}
//主要功能为设置当前需要操作的对象
function field($fieldname){
if(!$this->isVoid()&& $this->currentfield->isIncomplete()){
throw new \Exception("Incomplete field");
}
$this->enforceField($fieldname);
if(isset($this->fields[$fieldname]){
$this->currentfield = $this->fields[$fieldname];
} else {
$this->currentfield = new Field($fieldname);
$this->fields[$fieldname] = $this->currentfield;
}
return $this; //采用连贯语法
}
//字段集合是否为空
function isVoid(){
return empty($this->fields);
}
//检查字段是否合法
function enforceField ($fieldname){
if(!in_array($fieldname,$this->enforce) && !empty($this->enforce)){
$forcelist = implode(',',$this->enforce);
throw new \Exception("{$fieldname} not a legal field {$forcelist}");
}
}
//向字段对象添加where条件
function eq($value){
return $this->operator("=",$value);
}
function lt($value){
return $this->operator("operator(">",$value);
}
//向字段对象添加where条件
private function operator($symbol,$value){
if($this->isVoid){
throw new \Exception("no object field defined");
}
$this->currentfield->addTest($symbol,$value);
return $this; //采用连贯语法
}
//获取此类中所有字段对象集合的where条件数组
function getComps(){
$ret = array();
foreach($this->fields as $key => $field){
$ret = array_merge($ret,$field->getComps());
}
return $ret;
}
}
//客户端代码
$idobj = new IdentityObject ();
$idobj->field("name")->eq("The Good Show")->field("start")->gt(time())->lt(time()+(24*60*60));
$test = $idobj->getComps();
var_dump($test);
//输出类似下面的内容
/*
array{
array('name'=>'name','operator'=>'=','value'=>'The Good Show'),
array('name'=>'start','operator'=>'>','value'=>'123456'),//123456表示time()函数输出的时间戳
array('name'=>'start','operator'=>''123456')
}
*/
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