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I wrote a PHP version of MONGODB syntax parser, which can be queried through SQL-like syntax. I don’t know if anyone needs it, so please share it.

WBOY
WBOYOriginal
2016-08-08 09:31:551353browse

转载请注明作者:wetouns

在使用MONGODB的时候写查询语句总是一件让人蛋疼的事情,如果查询复杂一点,要嵌套好多层对象,于是我就想,能不能使用类似SQL的语法来进行查询呢,这样子代码看起来更加易懂,书写也更为简单,于是就花了些时间把这个想法变为现实该解析器会将类似SQL的语法转换成MONGODB的查询对象,目前条件判断只支持and和or,以及>,<,>=,<=,=的查询,还支持括号表示判断的优先级哦,更多的暂时不支持,想扩展的可以自己改源码,简单说明一下语法和用法吧

例1,我要查询a=0的文档

$query = new MongoQueryParser();
$query->query("a=0");
$queryRst = $query->result;<br>最终$queryRst的结果将会如下图
<p><img alt="" src="http://image.codes51.com/Article/image/20150101/20150101160034_8499.png"><br></p>
<p>例2:</p>
<p>这回来个复杂点的</p>
<pre code_snippet_id="569418" snippet_file_name="blog_20150101_2_7195815" name="code">$query = new MongoQueryParser();
$query->query("a=0 && b > 2");
$queryRst = $query->result;
结果如下


例3:

再来个更复杂的

$query = new MongoQueryParser();
$query->query("(a=0 && b > 2) || c <= 5");
$queryRst = $query->result;
结果如下

看完以上3个例子,相信不用说明用法,应该也会用了吧,嘿嘿,废话少说,贴上解析器的源码

<?php
class MongoQueryParser {
	function __construct() {
		$this->result =[];
	}
	
	public $result;
	
	public $leftFirstReg = "/\\(([^\\s]+)\\)(&&|\\|\\|)([^\\s]+$)/";//匹配左括号优先
	public $rightFirstReg = "/([^\\s]+?)(&&|\\|\\|)\\(([^\\s]+)\\)$/";//右括号优先
	public $allReg = "/\\(([^\\s]+)\\)(&&|\\|\\|)\\(([^\\s]+)\\)$/";//左右括号模式
	public $reg1 = "/([^\\s]+)(&&|\\|\\|)([^\\s]+)/";
	public $reg2 = "/([\\w]+)([=<>]+)([^\\s]+)/";
	public $opMap = [">"=>'$gt',"<"=>'$lt',">="=>'$gte',"<="=>'$lte'];
	private $meetOr = false;
	
	/**
	 * 将自定义的查询语句转换成MONGODB的查询语句
	 * 例1:a=3
	 * 例2:a>0&&a<2
	 * 例3:a>0&&a<2||c>3
	 */
	function query($query){
		$query =preg_replace("/\s/","",$query);
		$this->result = $this->exec($query,false,false);
		return $this->result;
	}
		
	function exec($query,$layer,$fromAnd){
		if(preg_match($this->allReg, $query,$matches1) > 0 || 
			preg_match($this->rightFirstReg, $query,$matches2) > 0 ||
			preg_match($this->leftFirstReg, $query,$matches3) > 0 || 
			preg_match($this->reg1, $query,$matches4)){
			$mat = null;
			$leftSame = false;
			$rightSame = false;
			if(count($matches1) > 0){
				$mat = $matches1;
			}else if(count($matches2) > 0){
				$leftSame = true;
				$rightSame = false;
				$mat = $matches2;
			}else if(count($matches3) > 0){
				$leftSame = false;
				$rightSame = true;
				$mat = $matches3;
			}else if(count($matches4) > 0){
				$leftSame = true;
				$rightSame = true;
				$mat = $matches4;
			}
			
			$op = $mat[2];
			$left = $mat[1];
			$right = $mat[3];
			
			if($op == "&&"){//如果操作符是AND
				$rst = null;
				if(!$layer || !$fromAnd){//如果不同层,或者调用来自上一层的or,那么就建立一个$and操作符
					$rst['$and'] = [];
					$larr = $this->exec($mat[1],$leftSame,true);
					$rarr = $this->exec($mat[3],$rightSame,true);
					$rst['$and'] = $this->mergeArr($rst['$and'],$larr, $rarr);
					return $rst;
				}else{//如果同层,直接把值都放到同层数组去
					$rst = array_merge($this->exec($mat[1],$leftSame,true),$this->exec($mat[3],$rightSame,true));
					return $rst;
				}
			}else if($op == "||"){
				if(!$layer || $fromAnd){//如果不同层
					$rst['$or'] = [];
					$larr = $this->exec($mat[1],$leftSame,false);
					$rarr = $this->exec($mat[3],$rightSame,false);
					$rst['$or'] = $this->mergeArr($rst['$or'],$larr, $rarr);
				}else{
					$rst = [];
					$rst = array_merge($this->exec($mat[1],$leftSame,false),$this->exec($mat[3],$rightSame,false));
				}
				return $rst;
			}
		}
		else{//如果最终已经分解成a=b的形式时,就在此解析
			preg_match($this->reg2, $query,$matches);
			if(count($matches) >= 4){
				$left = $matches[1];
				$op = $matches[2];
				$right = $matches[3];
				$rst = [];
				if($op == "="){
					if(is_numeric($right)){
						$rst[$left] = (float)$right;
					}else{
						$rst[$left] = $right;
					}
				}else{
					if(!isset($rst[$left])){
						$rst[$left] = [];
					}
					if(is_numeric($right)){
						$rst[$left][$this->opMap[$op]] = (float)$right;
					}else{
						$rst[$left][$this->opMap[$op]] = $right;
					}
				}
				return $rst;
			}
		}
	}
	
	function mergeArr($rst,$larr,$rarr){
		foreach ($larr as $lk=>$lv){
			$lcond = [];
			$lcond[$lk] = $lv;
			$rst[] = $lcond;
		}
			
		foreach ($rarr as $rk=>$rv){
			$rcond = [];
			$rcond[$rk] = $rv;
			$rst[] = $rcond;
		}
		return $rst;
	}
}

?>

好了,就这么多内容,我想应该会有人需要的
有什么问题直接留言吧

以上就介绍了写了一个PHP版本的MONGODB语法解析器,可以通过类似SQL的语法来进行查询,不知道有人需要不,分享一下吧,包括了方面的内容,希望对PHP教程有兴趣的朋友有所帮助。

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