I have many JSON array with different types of nodes in it.
Sample Json 1:
[
{
"EmpID": "23",
"EmpName": "Jhon",
"Age": "23"
},
{
"EmpID": "29",
"EmpName": "Paul",
"Age": "25"
},
{
"EmpID": "123",
"EmpName": "Jack",
"Age": "29"
},
{
"EmpID": "129",
"EmpName": "Apr",
"Age": "29"
}
]
Sample Json 2
[
{
"DepID": "2",
"Name": "Sales"
},
{
"DepID": "5",
"Name": "Marketing"
},
{
"DepID": "12",
"Name": "IT"
}
]
I want to filter them based on different conditions such as
1)EmpID=29
This should return
[
{
"EmpID": "29",
"EmpName": "Paul",
"Age": "25",
}
]
2)Age=23 and EmpName=Jhon
This should return
[
{
"EmpID": "23",
"EmpName": "Jhon",
"Age": "23"
}
]
Age=29
This should return
[
{
"EmpID": "123",
"EmpName": "Jack",
"Age": "29"
},
{
"EmpID": "129",
"EmpName": "Apr",
"Age": "29"
}
]
So I need a generic approach to do any number of filters on the JSON array. I am planning to get all the filters using some comma separated string like Age="23",EmpName="Jhon" and this can be converted to any format in the code.
I have tried creating dynamic filter using Json Path such as $.[?(#.Age == '23' && #.EmpName == 'Jhon')].
Also I tried using LINQ like
var result = JsonConvert.DeserializeObject(jsonString);
var res = (result as Newtonsoft.Json.Linq.JArray).Where(x =>
x["Age"].ToString() =="23" && x["EmpName"].ToString()=="Jhon").ToList();
But how I can generate the where conditions dynamically based on any number of conditions I receive
Also there is a plan to include Date filters in case there is some datetime nodes in json such as BirthDate>12051995.
I am not sure how I can dynamically filter using any number of input filter conditions.
To get this working in a traditional way, you'll need to perform 3 steps:
define a class to contain the data
deserialize the json into a list of objects
use linq to query your selection
You can do the same thing for the departments.
If you need to join them in any way, use .Join. If the JSON is mixed, you can create a single class containing all the properties and use that to query.
So for the simple case: first define a class to represent you object:
public class Employee
{
public int EmpID {get;set;}
public string EmpName {get;set;}
public int Age {get;set;}
}
Then deserialize and query:
put at the top:
using System.Text.Json;
public void Main()
{
//deserialize into a list
List<Employee> employees =
JsonSerializer.Deserialize<List<Employee>>(yourJsonString);
//query
var result = employees.Where(c => c.Age == 23 && c.EmpName == "Jhon");
//show results
foreach (var employee in result)
Console.WriteLine(employee.EmpID);
}
As by update:
Depending on your use case you have a couple of options:
a fixed number of dynamic properties
a truly dynamic query
A fixed number of dynamic properties
You can achieve a more dynamic setup with the following:
//define the filterable properties
//note they are nullable
int? age = null;
int? id = null;
string name = null;
//apply them in a query
//
//note: if one of the filter properties is not set,
// that side of the && expression evaluates to "true"
var result = employees.Where(c => (age == null ? true : c.Age == age) &&
(id == null ? true : c.EmpId == id) &&
(name == null ? true : c.EmpName == name));
a truly dynamic query
Now here things start to get tricky. One possible option is to generate a string based query, with the help of a libary like Dynamic Linq
You have almost nailed it. :)
Instead of using DeserializeObject and then converting it to JArray prefer JArray.Parse
var json = File.ReadAllText("sample.json");
var semiParsedJson = JArray.Parse(json);
Instead of using ToList after Where prefer JArray constructor which can work well with an IEnumerable<JToken>
const string IdField = "EmpID", NameField = "EmpName", AgeField = "Age";
const StringComparison caseIgnorant = StringComparison.OrdinalIgnoreCase;
var idEq29 = semiParsedJson.Children()
.Where(token => string.Equals(token[IdField].Value<string>(),"29", caseIgnorant));
Console.WriteLine(new JArray(idEq29).ToString());
The other queries can be implemented in the very same way
var ageEq23AndNameJhon = semiParsedJson.Children()
.Where(token => string.Equals(token[AgeField].Value<string>(), "23", caseIgnorant)
&& string.Equals(token[NameField].Value<string>(), "Jhon", caseIgnorant));
Console.WriteLine(new JArray(ageEq23AndNameJhon).ToString());
var ageEq29 = semiParsedJson.Children()
.Where(token => string.Equals(token[AgeField].Value<string>(), "29", caseIgnorant));
Console.WriteLine(new JArray(ageEq29).ToString());
UPDATE #1: Enhance proposed solution
With the following extension method
public static class JArrayExtensions
{
public static JArray Filter(this JArray array, Func<JToken, bool> predicate)
=> new JArray(array.Children().Where(predicate));
}
you can greatly simplify the filtering
var idEq29 = semiParsedJson
.Filter(token => string.Equals(token[IdField].Value<string>(),"29", caseIgnorant));
var ageEq23AndNameJhon = semiParsedJson
.Filter(token => string.Equals(token[AgeField].Value<string>(), "23", caseIgnorant))
.Filter(token => string.Equals(token[NameField].Value<string>(), "Jhon", caseIgnorant));
var ageEq29 = semiParsedJson
.Filter(token => string.Equals(token[AgeField].Value<string>(), "29", caseIgnorant));
Console.WriteLine(idEq29);
Console.WriteLine();
Console.WriteLine(ageEq23AndNameJhon);
Console.WriteLine();
Console.WriteLine(ageEq29);
Or you can push it even further. If all the fields store string values then you can define the extension method like this:
public static class JArrayExtensions
{
public static JArray Filter(this JArray array, string field, string value)
=> new JArray(array.Children().Where(GenerateFilter(field, value)));
private static Func<JToken, bool> GenerateFilter(string field, string value)
=> (JToken token) => string.Equals(token[field].Value<string>(), value, StringComparison.OrdinalIgnoreCase);
}
The the filter queries are super simple :D
var idEq29 = semiParsedJson
.Filter(IdField,"29");
var ageEq23AndNameJhon = semiParsedJson
.Filter(AgeField, "23")
.Filter(NameField, "Jhon");
var ageEq29 = semiParsedJson
.Filter(AgeField, "29");
Console.WriteLine(ageEq23AndNameJhon);
Console.WriteLine();
Console.WriteLine(idEq29);
Console.WriteLine();
Console.WriteLine(ageEq29);
Related
I'm new to LINQ and having a problem I can't seem to solve. I have a JSON array/object like this:
[
{
"items": [
"pepperoni"
]
},
{
"items": [
"sausage"
]
},
{
"items": [
"sausage"
]
},
{
"items": [
"pepperoni",
"mushrooms",
"olives"
]
},
{
"items": [
"peppers",
"spinach"
]
},
{
"items": [
"peppers",
"spinach"
]
},
{
"items": [
"peppers",
"spinach"
]
}
]
I need to GROUP BY the items combinations and produce results like this:
peppers,spinach - 3
sausage - 2
pepperoni - 1
pepperoni,mushrooms,olives - 1
This is the Linq query I have (clearly doesn't work).
JArray jsonData= JsonConvert.DeserializeObject<JArray>(jsonString);
var queryResult =
from c in jsonData.Select(i => i["items"]).Values<string>()
group c by c
into g
orderby g.Count() descending
select new { Items = g.Key, Count = g.Count() };
I find examples for every scenario except this one.
You need to merge list items into string then Group items:
var queryResult = from c in jsonData.Select(i => String.Join(",", i["items"]).OrderBy(o => o))
group c by c
into g
orderby g.Count() descending
select new { Items = g.Key, Count = g.Count() };
It will give you desired output:
peppers,spinach-3
sausage-2
pepperoni-1
pepperoni,mushrooms,olives-1
There's another solution with the use of SequenceEqual and IEqualityComparer.
This solution is longer but more complete, since it uses proper custom equality comparer.
First we need a class implementing IEqualityComparer
public class ItemEqualityComparer : IEqualityComparer<IEnumerable<string>>
{
public bool Equals(IEnumerable<string> x, IEnumerable<string> y)
{
if (x == null && y == null)
return true;
else if (x == null || y == null)
return false;
return x.SequenceEqual(y);
}
public int GetHashCode(IEnumerable<string> obj)
{
return obj.Select(o => o.GetHashCode()).Sum();
}
}
then we can use it to group the items correctly:
var itemsGroups = jsonData.Select(i => i["items"].Values<string>()).GroupBy(l => l, l => l, (key, values) => new
{
Key = key,
Count = values.Count()
}, new ItemEqualityComparer());
This solution keeps the items inside a list so that you don't have to resplit them from the joint string.
The drawback is that is slower becausxe it has to enumerate all the items of all the lists to check that there're equals.
I hope I was helpful.
I'm searching a json file, with the following structure:
{
"objects": [
{
"name": "obj1",
"state": {
"type": 4,
"childs": [
"state": {
"type": 5,
...
The state can contain state as a child until any number of Levels. Now im trying to find all objects containing a certain Patterns of states, e.g. state 4 with child state 5 with child state 2.
My code so far is this.
JObject o = JObject.Parse(System.IO.File.ReadAllText(#"j.json"));
var oObjects=
from p in o["objects"]
where (string)p["state"] == "4"
select (string)p["name"];
How can I expand the code to find all objects containing the search pattern on any Level?
To make it work for indefinite level, then you will need to use a recursive method like the following:
void Main()
{
var str = #"{
""objects"": [
{
""name"": ""obj1"",
""state"": {
""type"": 4,
""childs"": [
{
""state"": {
""type"": 5
}
}
]
}
}
]
}";
var obj = JObject.Parse(str);
GetValidObjects(obj, new string[] { "4", "5" }); // Name list of valid objects
}
And the helper methods defined like:
public IEnumerable<string> GetValidObjects(JObject obj, IEnumerable<string> values)
{
return obj["objects"]
.Where(i => (string)i["state"]["type"] == values.First() && ContainsState((JArray)i["state"]["childs"], values.Skip(1)))
.Select(i => (string)i["name"]);
}
public bool ContainsState(JArray childs, IEnumerable<string> values)
{
if (childs == null)
{
return values.Count() == 0;
}
return childs.Any(i => (string)i["state"]["type"] == values.First() && ContainsState((JArray)i["state"]["childs"], values.Skip(1)));
}
An option could be to convert the json to xml and then use an xpath query to obtain the list of nodes.
string json = System.IO.File.ReadAllText(#"j.json");
XmlDocument document = (XmlDocument)JsonConvert.DeserializeXmlNode(json);
XmlNodeList nodes = document.SelectNodes("//name[../state[type[.=4] and childs/state[type[.=5] and childs/state[type[.=2]]]]]");
You can use SelectTokens for this:
var objects = o.SelectTokens("$.objects[?(#.state.type == 4
&& #.state.childs[*].state.type == 5)].name")
.Select(s => (string)s)
.ToList();
I have a linq statement which includes a Contain() method. I am using this so that I can select all from an array where name is not null but only select the objects from the array1 that contains the same name in object array2.
I have managed to return the result but its displaying true or false where as I need the object values.
The code
var response = JsonConvert.DeserializeObject<FamilyNames>(result);
List<object> data = new List<object>();
ClassName className = new ClassName();
object [] getNames = className.GetType()
.GetProperties()
.Select(p =>
{
object value = p.Name;
return value == null ? null : value.ToString();
})
.ToArray();
foreach (var obj in response.items.Where(n => n.name != null).DistinctBy(x => x.name).Select(a => getNames.Contains(a.initialName)))
{
data.Add(obj);
}
client.Dispose();
return Json(data, JsonRequestBehavior.AllowGet);
}
The result is :
["True","False","True"]
If I don't use the select statement then I get my objects:
[
{
"initalName": "BD",
"firstName": "Bob",
"LastName": "Dilan"
},
{
"initalName": "HT",
"firstName": "Harry", // the initialName doesn't exist in list so need to remove this object
"LastName": "Thomas"
},
{
"initalName": "LJ",
"firstName": "Lindsey",
"LastName": "Jones"
}
]
The initalName is not present in getNames array so needs to be removed. Any advice would be much appreciated, especially on the approach. The desired result would be:
[
{
"initalName": "BD",
"firstName": "Bob",
"LastName": "Dilan"
},
{
"initalName": "LJ",
"firstName": "Lindsey",
"LastName": "Jones"
]
The problem is, that in this LINQ expression, at the end you are selecting a Bool as an output. (.Contains() returns a bool).
From this reason, your expression will retunr a list of Bool.
response.items
.Where(n => n.name != null)
.DistinctBy(x => x.name)
.Select(a => getNames.Contains(a.initialName))
To acheave what you want, simply replace the .Select() with a .Where(), what will do the intended filtering and keep the original objects as they are, (will not do any projection) and you will get the expected outcome:
response.items
.Where(n => n.name != null)
.DistinctBy(x => x.name)
.Where(a => getNames.Contains(a.initialName))
Suppose I have a List of dynamic objects like:
var records = [
{
"Id": 1,
"Name": "sai",
"Age": "4",
"About": "12.02.1991"
},
{
"Id": 2,
"Name": "hjfh",
"Age": "2",
"About": "12.02.1991"
},
{
"Id": 3,
"Name": "hello name",
"Age": "6",
"About": "hi"
},
{
"Id": 4,
"Name": 1,
"Age": "9",
"About": "hello world"
}
]
string searchString = "Hello";
I tried something like:
foreach (var item in records )
{
foreach (var field in item)
{
if (field.Value != null && field.Value.ToString().IndexOf(query.SearchString, StringComparison.OrdinalIgnoreCase) >= 0)
{
count++;
break;
}
}
}
I want the count of records which has searchString at any field in the record. but can I write this using a LINQ query?
This is your code, converted to a linq expression:
You have access to the field and the object in the select statement.
records.Cast<ExpandoObject>().SelectMany(x => x, (obj, field) => new { obj, field })
.Where(x => x.field.Value != null && x.field.Value.ToString().IndexOf(SearchString, StringComparison.OrdinalIgnoreCase) >= 0)
.Select(x => x.field.Key);
To count the number of objects that have at least one field that contains the searchstring:
records.Cast<ExpandoObject>()
.Where(x => x.Any(y => y.Value != null && y.Value.ToString().IndexOf(SearchString, StringComparison.OrdinalIgnoreCase) >= 0))
.Count();
It would be something like this:
logic:
var qry = records.Where(x=>x.Field.Contains(searchedstring)).Count();
real example:
var qry = records.Where(x=>x.Name.Contains("sai")).Count();
Below is the simplest code.
int count = records.Count(x => x.Name.StartsWith("hello") || x.About.StartsWith("hello"));
I have two JToken's that represent JSON arrays of objects and I would like to merge them. JToken has a method Concat but it produces null as result when I try to use it.
Action<JToken> Ok = (x) =>
{
Debug.WriteLine(x);
/* outputs
[
{
"id": 1,
},
{
"id": 2,
}
]
*/
x = (x).Concat<JToken>(x) as JToken;
Debug.WriteLine(x); // null
};
How can I make it work?
Use JContainer.Merge() with MergeArrayHandling.Concat.
This is available starting with Json.NET 6 Release 4. So if your arrays are in a JContainer (e.g. a JObject), this is a simple and robust solution.
Example:
JObject o1 = JObject.Parse(#"{
'FirstName': 'John',
'LastName': 'Smith',
'Enabled': false,
'Roles': [ 'User' ]
}");
JObject o2 = JObject.Parse(#"{
'Enabled': true,
'Roles': [ 'Operator', 'Admin' ]
}");
o1.Merge(o2, new JsonMergeSettings { MergeArrayHandling = MergeArrayHandling.Concat });
string json = o1.ToString();
// {
// "FirstName": "John",
// "LastName": "Smith",
// "Enabled": true,
// "Roles": [
// "User",
// "Operator",
// "Admin"
// ]
// }
JToken.FromObject(x.Concat(x))
I needed same, here's what I came up with
https://github.com/MrAntix/Newtonsoft.Json/blob/master/Src/Newtonsoft.Json/Linq/MergeExtensions.cs
public static void MergeInto(
this JContainer left, JToken right, MergeOptions options)
{
foreach (var rightChild in right.Children<JProperty>())
{
var rightChildProperty = rightChild;
var leftPropertyValue = left.SelectToken(rightChildProperty.Name);
if (leftPropertyValue == null)
{
// no matching property, just add
left.Add(rightChild);
}
else
{
var leftProperty = (JProperty) leftPropertyValue.Parent;
var leftArray = leftPropertyValue as JArray;
var rightArray = rightChildProperty.Value as JArray;
if (leftArray != null && rightArray != null)
{
switch (options.ArrayHandling)
{
case MergeOptionArrayHandling.Concat:
foreach (var rightValue in rightArray)
{
leftArray.Add(rightValue);
}
break;
case MergeOptionArrayHandling.Overwrite:
leftProperty.Value = rightChildProperty.Value;
break;
}
}
else
{
var leftObject = leftPropertyValue as JObject;
if (leftObject == null)
{
// replace value
leftProperty.Value = rightChildProperty.Value;
}
else
// recurse object
MergeInto(leftObject, rightChildProperty.Value, options);
}
}
}
}