KQL.NET

KQL (Keywords Query Language) with LINQ methods in dotnet

What is Keyword Query Language (KQL)?

KQL is a free text-keyword and property restrictions query used to search in SharePoint. You can read more about it KQL syntax

Motivation

We were asked in one of our project to build an free query syntax to build search over an collection of data (IEnumerable, etc). After some research, we found that KQL (Keyword Query Language) syntax is best suited to our need.

Adom.KQL transforms a KQL to a Linq expression to be used in an IEnumerable

Installation

Adom.KQL can be found here on NuGet and can be installed by copying and pasting the following command into your Package Manager Console within Visual Studio (Tools > NuGet Package Manager > Package Manager Console).

Install-Package Adom.KQL

Alternatively, you can install Adom.KQL via the CLI with the following command:

dotnet add package Adom.KQL

Usage

// Let's define an class
public class TestClass
{
    public string? StringField { get; set; }
    public int NumberField { get; set; }
    public DateTime DateTimeField { get; set; }
    public DateOnly DateOnlyField { get; set; }
}

// we can build the query linq expression using 
// the KqlEngine
var expression = KqlEngine.Parse<TestClass>("StringField = 'value' or NumberField != 10");

// we can directly filter the IEnumerable with
// the KqlEngine
var datas = new List<TestClass>();
var result = KqlEngine.ProcessQuery<TestClass>(datas, "StringField = 'value' or NumberField != 10");

LINQ Methods with KQL

You can use some LINQ methods directly with a KQL query.

• Where IEnumerable<T>.Where<T>(string kqlQuery)
• First IEnumerable<T>.First<T>(string kqlQuery)
• FirstOrDefault IEnumerable<T>.FirstOrDefault<T>(string kqlQuery)
• Any IEnumerable<T>.Any<T>(string kqlQuery)
• Count IEnumerable<T>.First<T>(string kqlQuery)

Limitations

Adom.KQL works only on IEnumerable of reference object type (any class with properties like DateTime, int/uint/long/ulong/decimal, string, bool).

Feature in development

• Query with IEnumerable<datetime / dateonly / int / long / decimal / string / bool>
• Support Class with nested class properties
• Contains operator -e.g. 'StringField = 'value*' (startswith) / '*value' (endswith) / '*value*' (contains)
• math calculation on query -e.g. (NumberField1 +-*/ NumberField...) (>=, =, !=) NumberValue

Contribution

This project welcomes any contribution. Feel free to submit a PR or open an Issue. You can read our [Code of contribution]

Links

• KQL syntax

License

This project is licensed under the terms of the MIT license.