NHQueryBuilder

NHQueryBuilder is a fluent, strongly-typed query builder for NHibernate, designed to simplify and streamline the construction of complex queries in .NET applications. It provides a modern, expressive API for building criteria, projections, ordering, pagination, and more, all while leveraging the power of NHibernate ORM.

Features

• Fluent API for Query Construction: Build queries using a chainable, strongly-typed syntax.
• Comprehensive Condition Support: Easily add conditions such as Equal, NotEqual, IsIn, IsNotIn, IsNull, IsNotNull, Between, Like, NotLike, GreaterThan, GreaterThanOrEqual, LessThan, LessThanOrEqual.
• Ordering: Add ascending or descending order by clauses.
• Pagination: Use Skip and Take for efficient paging of results.
• Projections: Select specific fields, collections, or custom types (including anonymous types and DTOs).
• Fetching (Joins): Eagerly fetch related entities with Fetch.
• Count Queries: Get the count of entities matching any set of conditions.
• Integration with NHibernate: Seamlessly integrates with NHibernate's ISession and ICriteria APIs.
• Type-safe Property Access: All property references are strongly-typed, reducing runtime errors.
• Unit Tested: Includes a suite of unit tests for all major features.

Getting Started

1. Define Your Entities

public class Author
{
    public virtual int Key { get; set; }
    public virtual string Name { get; set; }
    public virtual string Email { get; set; }
    public virtual string Country { get; set; }
    public virtual IList<Book> Books { get; set; }
}

public class Book
{
    public virtual int Key { get; set; }
    public virtual string Title { get; set; }
    public virtual string Genre { get; set; }
    public virtual Author Author { get; set; }
}

2. Build Queries with FluentConditions

using (ISession session = ...)
{
    var conditions = new FluentConditions<Author>()
        .Equal(x => x.Country, "India")
        .IsNotNull(x => x.Email)
        .OrderByAscending(x => x.Name)
        .Skip(10)
        .Take(10);

    var authors = session.GetList(conditions);
}

3. Projections and Custom Results

// Select only names
conditions.Select(x => x.Name);
var names = session.GetProjectedList(conditions);

// Project to a custom DTO
conditions.Select(x => new { x.Key, x.Name, x.Email });
var dtos = session.GetProjectedList<Author, SimpleResult>(conditions);

4. Fetching Related Entities

conditions.Fetch(x => x.Books);

5. Count Queries

int count = session.GetCount(conditions);

Supported Condition Methods

• Equal, NotEqual
• IsIn, IsNotIn
• IsNull, IsNotNull
• Between
• Like, NotLike
• GreaterThan, GreaterThanOrEqual, LessThan, LessThanOrEqual
• OrderByAscending, OrderByDescending
• Select (projections)
• Fetch (joins)
• Skip, Take (pagination)

Example Usage

See NHQueryBuilder.Example/Program.cs for comprehensive usage examples, including projections, joins, and pagination.

Requirements

• .NET 8
• NHibernate

License

MIT License