Where

• Path function Where is used to select items in a collection (i.e., JSON array or a collection resulted by evaluation of other JsonQL functions, such as ‘Where’, ‘Select’, etc.).

Function Parameters

• criteria:

  • Required: No

  • Type: lambda function of type “x => boolean”

  • Description: A criteria used to filter the result.

Example

Note

The following JSON files are referenced in JsonQL expressions in Example.json in example below: Companies.json.

Example.json below demonstrates using Where path function.

{
  "WhereExample":
    "$value(Companies.Where(c => c.Data.Address.State != 'CO').Select(c => c.Employees.Where(e => e.Age < 40)).Where(e => e.Id != 100000010).Last())"
}

The result (i.e., an instance of JsonQL.Compilation.ICompilationResult) is serialized to a Result.json file below.

Note

For brevity, the serialized result includes only serialized evaluated Example.json and does not include parent JSON files in JsonQL.Compilation.ICompilationResult.CompiledJsonFiles

{
  "CompiledJsonFiles":[
    {
      "TextIdentifier": "Example",
      "CompiledParsedValue":
      {
        "WhereExample": {
          "Id":  100000008,
          "Name":  "Laura Lee",
          "Address": {
            "Street":  "258 Willow Lane",
            "City":  "San Diego",
            "State":  "CA",
            "ZipCode":  "92101"
          },
          "Salary":  105500,
          "Age":  32
        }
      }
    }
  ],
  "CompilationErrors":
  {
    "$type": "System.Collections.Generic.List`1[[JsonQL.Compilation.ICompilationErrorItem, JsonQL]], System.Private.CoreLib",
    "$values": []
  }
}

The code snippet shows how the JSON file Example.json was parsed using JsonQL.Compilation.IJsonCompiler

// Set the value of jsonCompiler to an instance of JsonQL.Compilation.IJsonCompiler here.
// The value of JsonQL.Compilation.JsonCompiler is normally created by Dependency Injection container
// and it is normally configured as a singleton.
JsonQL.Compilation.IJsonCompiler jsonCompiler = null!;

var sharedExamplesFolderPath = new[]
        {
            "DocFiles", "MutatingJsonFiles", "Examples"
        };

var companiesJsonTextData = new JsonTextData("Companies",
    LoadJsonFileHelpers.LoadJsonFile("Companies.json", sharedExamplesFolderPath));

var result = jsonCompiler.Compile(new JsonTextData("Example",
    this.LoadExampleJsonFile("Example.json"), companiesJsonTextData));