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;
例3:
再来个更复杂的
$query = new MongoQueryParser(); $query->query("(a=0 && b > 2) || c <= 5"); $queryRst = $query->result;
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; } } ?>
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。