Angularjs：从匹配某些条件的数组中获取行

Question

我有一个像这样的数组

var hospitals=[{"distric_id":"1","type":"c","details":[{"name":"hello","address":"hello","number":"686678"}]},
   {"distric_id":"1","type":"g","details":[{"name":"hello","address":"hello","number":"686678"}}]}
   ]

现在我需要从满足某些条件的数组中获取行。 这是代码sn-p

 //loop through the array and fecth some rows based on some condition
function getHospitals(id,type){
  var hospitals=[{"district_id":"1","type":"c","details":[{"name":"hello","address":"hello","number":"686678"}]},
       {"district_id":"1","type":"g","details":[{"name":"hello","address":"hello","number":"686678"}}]}
       ]
  //return array of results
  return result;
}

result 数组包含来自hospitals 数组的符合条件的行 像 select * from where district_id=id and type=type 那么如何从上面的数组中选出符合上述条件的一行呢？

Answer 1

您可以使用 Lodash 来执行此操作。 https://lodash.com/docs#findWhere

来自 lodash：

var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
];

_.result(_.findWhere(users, { 'age': 36, 'active': true }), 'user');
// → 'barney'

_.result(_.findWhere(users, { 'age': 40, 'active': false }), 'user');
// → 'fred'

lodash中有很多搜索函数：find() findIndex(), ...

Answer 2

目前还不存在基于 JavaScript 数组的成熟 SQL 解析器和存储系统。有一些已弃用和实验性的东西像this sql parser 这样只支持 SELECT 语句，但我强烈建议不要这样做。

相反，您可能想看看lodash（或underscore）。它们都有很多高级实用功能，可以让处理数组和其他类型的集合变得更加容易。

例如

select * from where district_id=id and type=type

可以这样实现：

var matchingHospitals = _.where(hospitals, {district_id: id, type: type});

注意：_.where 返回一个数组。

另外，如果_.where不剪，还有_.filter、_.find等等……

Answer 3

你可以使用 jQuery 的 'grep' 函数来完成：

function getHospitals(id, type){
    var hospitals=[
        {"district_id":"1","type":"c","details":[{"name":"hello","address":"hello","number":"686678"}]},
        {"district_id":"1","type":"g","details":[{"name":"hello","address":"hello","number":"686678"}}]}
    ];

    //return array of results
    return $.grep(hospitals, function(e){
        return (e.district_id == id && e.type == type);
    });
}

希望这会有所帮助。

Answer 4

    //loop through the array and return all rows satisfying the conditions
    function getHospitals(id,type){
  var hospitals=[{
    "district_id":"1","type":"c","details":[{"name":"hello","address":"hello","number":"686678"}]
  },{"district_id":"1","type":"g","details":{"name":"hello","address":"hello","number":"686678"}}];
  var matchingHospitals = []; //an array to save all the matching hospitals that satisfy the condition
  for(var i in hospitals){  //loop through the data
    var hospital = hospitals[i];
    if(hospital.district_id==id && hospital.type==type){ //check condition
      matchingHospitals.push(hospital);    //push into matching array
    }
  }

  //return array of results
  return matchingHospitals;   //return matching hospitals array
}

测试查询：

getHospitals("1","c")