mongodb 分组查询

Posted on 2015-07-02 02:36  小蕊同学  阅读(738)  评论(0)  编辑  收藏  举报
数据的保存
  1. include_once 'mDB.class.php';
  2. $m=new mDB();
  3. $m->setDB('mydb');
  4. // $m->save('stu',['dept'=>'财务','name'=>'张三','age'=>73]);
  5. // $m->save('stu',['dept'=>'计算机','name'=>'张四','age'=>53]);
  6. // $m->save('stu',['dept'=>'计算机','name'=>'张五','age'=>23]);
  7. // $m->save('stu',['dept'=>'财务','name'=>'张六','age'=>93]);
  8. // $m->save('stu',['dept'=>'计算机','name'=>'张七','age'=>83]);
  9. // $m->save('stu',['dept'=>'法学','name'=>'张八','age'=>53]);
查询出所有的专业
  1. $db=$m->getMongoClient();
  2. $d=$db->mydb;
  3. $c=$d->stu;
  4. // echo $c->find(['dept'=>'计算机'])->count();//返回计算机专业有几人
  5. $currsor=$c->find([],['_id'=>0,'dept'=>1]);
  6. foreach ($currsor as $v){
  7.     echo $v['dept'].'<br>';
  8. }

消除重复取出各个专业的名字distinct
  1. $db=$m->getMongoClient();
  2. $d=$db->mydb;
  3. $c=$d->stu;
  4. $depts=$c->distinct('dept');
  5. foreach ($depts as $v){
  6.     echo $v.'<br>';
  7. }

统计各个专业的人数
  1. include_once 'mDB.class.php';
  2. $m=new mDB();
  3. $m->setDB('mydb');
  4. $db=$m->getMongoClient();
  5. $d=$db->mydb;
  6. $c=$d->stu;
  7. $depts=$c->distinct('dept');
  8. foreach ($depts as $v){
  9.     echo $v;
  10.     echo '专业人数'.$c->find(['dept'=>$v])->count();
  11.     echo '<hr>';
  12. }

分组查询的所有代码
  1. <?php
  2. header('content-type:text/html;charset=UTF-8');
  3. //无密码直接登录mongodb
  4. $m = new MongoClient('mongodb://localhost:27017');
  5. $db = $m->selectDB('aaa');
  6. $c1 = $db->student;
  7. //$c1->insert(array("category" => "计算机", "name" => "张在",'age'=>33));
  8. //$c1->insert(array("category" => "计算机", "name" => "李四",'age'=>25));
  9. //$c1->insert(array("category" => "英语", "name" => "赵六",'age'=>30));
  10. //$c1->insert(array("category" => "英语", "name" => "赵七",'age'=>40));
  11. //$c1->insert(array("category" => "会计", "name" => "李勇",'age'=>10));
  13. //$keys = array("category" => 1);
  14. //$initial = array("items" => array());
  15. //$reduce = "function (obj, prev) { prev.items.push(obj);}";
  16. //$reduce = "function (obj, prev) { prev.items.push(obj.name);}";
  17. //$reduce = "function (obj, prev) { prev.items.push(obj.name+obj.age);}";
  18. //$g = $c1->group($keys, $initial, $reduce);
  19. //echo json_encode($g['retval']);
  20. //echo '<pre>';
  21. //print_r($g);
  24. //统计各专业人数
  25. // $keys = array("category" => 1); //指定分类属性
  26. // $initial = array("count" => 0);
  27. // $reduce = "function (obj, prev) { prev.count++; }";
  28. // $condition = array('condition' => array());//条件
  29. // $g = $c1->group($keys, $initial, $reduce, $condition);
  30. // var_dump($g);
  32. //统计年龄大于等于25岁的总人数
  33. // $keys=[];
  34. // $initial = ['c'=>0];
  35. // $reduce = 'function(obj,prev){prev.c++;}';
  36. // $where = ['condition'=>['age'=>['$gte'=>25]]];
  37. // $g = $c1->group($keys,$initial,$reduce,$where);
  38. // var_dump($g);
  40. //求出各专业学生年龄之和    select category,sum(age) from student group by category;
  41. // $keys=['category'=>1];
  42. // $initial = ['sum'=>0];
  43. // $reduce = "function(obj,prev){prev['sum'] += obj.age; }";
  44. // $g = $c1->group($keys,$initial,$reduce);
  45. // var_dump($g);
  47. //根据专业，来统计各专业的最大年龄
  48. // $keys=['category'=>1];
  49. // $initial = ['max'=>0];
  50. // $reduce = "function(obj,prev){if(obj.age>prev['max']){prev['max']=obj.age;} }";
  51. // $g = $c1->group($keys,$initial,$reduce);
  52. // var_dump($g);
  54. //根据专业分组，求出每个专业的人数，平均年龄，年龄总各
  55. $keys=['category'=>1];
  56. $initial = ['sum'=>0,'count'=>0,'avg'=>0];
  57. $reduce = "function(obj,prev){prev['sum'] += obj.age;prev['count']++;prev['avg']=prev['sum']/prev['count']}";
  58. $g = $c1->group($keys,$initial,$reduce);
  59. var_dump($g);
  60. $m->close();
查询出所有的信息
  1. include_once 'mDB.class.php';
  2. $m=new mDB();
  3. $m->setDB('mydb');
  4. $db=$m->getMongoClient();
  5. $d=$db->mydb;
  6. $c=$d->stu;
  7. $keys = ["dept" => 1]; //指定分类属性
  8. $initial = array("count" => 0);
  9. $reduce = "function (obj, prev) { prev.count++; }";
  10. $condition = array('condition' => array());//条件
  11. $g = $c->group($keys, $initial, $reduce, $condition);
  12. echo '<pre>';
  13. var_dump($g);

统计出所有的信息
$reduce = "function (obj, prev) { prev.count++; }";此句为程序里面的死命令
  1. <?php 
  2. include_once 'mDB.class.php';
  3. $m=new mDB();
  4. $m->setDB('mydb');
  5. $db=$m->getMongoClient();
  6. $d=$db->mydb;
  7. $c=$d->stu;
  8. $keys = ["dept" => 1]; //指定分类属性
  9. $initial = array("count" => 0);
  10. $reduce = "function (obj, prev) { prev.count++; }";
  11. $condition = array('condition' => array());//条件
  12. $g = $c->group($keys, $initial, $reduce, $condition);
  13. echo '<pre>';
  14. var_dump($g);
  15. echo '总人数'.$g['count'];
  16. echo '<br>总专业'.$g['keys'].'个专业<br>';
  17. foreach ($g['retval'] as $v){
  18.     echo $v['dept'].'人数'.$v['count'].'人';
  19. }

"function(obj,prev){
    prev['sum'] += obj.age;
    prev['count']++;
    prev['avg']=prev['sum']/prev['count'];
   if(obj.age>prev['max']){prev['max']=obj.age;}
    if(obj.age<prev['min']){prev['min']=obj.age;}
}";  
求出平均分，最高分，最低分，各专业的总分
  1. <?php 
  2. include_once 'mDB.class.php';
  3. $m=new mDB();
  4. $m->setDB('mydb');
  5. $db=$m->getMongoClient();
  6. $d=$db->mydb;
  7. $c=$d->stu;
  8. //根据专业分组，求出每个专业的人数，平均年龄，年龄总各
  9. $keys=['dept'=>1];
  10. $initial = ['sum'=>0,'count'=>0,'avg'=>0,'max'=>0,'min'=>100];
  11. $reduce ="function(obj,prev){
  12.     prev['sum'] += obj.age;
  13.     prev['count']++;
  14.     prev['avg']=prev['sum']/prev['count'];
  15.    if(obj.age>prev['max']){prev['max']=obj.age;}
  16.     if(obj.age<prev['min']){prev['min']=obj.age;}
  17. }";  
  18. $g = $c->group($keys,$initial,$reduce);
  19. echo '<pre>';
  20. var_dump($g);
  21. foreach ($g['retval'] as $v){
  22. echo  $v['dept'].'平均分'.$v['avg'].'最高分'.$v['max'].'最低分'.$v['min'].'各专业总分为'.$v['sum'].'<br>';
  23. }





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