DotNetBrightener.LinQToSqlBuilder 2025.0.6-preview-455

LinQ to SQL Builder - small .NET library supports creating SQL queries and commands in a strongly typed fashion.

© 2025 DotNet Brightener

Inspiration

I am a big fan of ORM, and I have been using Entity Framework since the first day I started my career as a .Net Developer back in 2009.

Some time ago I woked on a project and needed to deal with 2 databases at the same time. For some reasons, I am not supposed to use Entity Framework for the second database which is dynamically configured in a tenant-based setting at runtime. So I have to choose either to come back to ADO.Net and making queries using string concatenation and SqlCommand, or I to come up with something that is friendly with Entity Framework usage, which is using Linq lambda expression to describe the query or command we want to process with the database.

Searching through the internet, I found a few repositories that seem to fit my needs, but I still reluctant because they all seem to miss something. For instance, the open-source library from https://github.com/mladenb/sql-query-builder does most of the operations that we need for basic usages, but the queries and commands are built on top of strings.

Finally, I found the open-source repository at https://github.com/DomanyDusan/lambda-sql-builder and it's very close to what I am looking for. However, the author has not continued supporting the project and its last commit was 7 years prior to the time I started developed this library. So I decided to reference his code and make a modified version of what he had done, and adding support for INSERT, UPDATE, DELETE instead of only SELECT queries as in the original version.

This project is not meant to replace or to cover the entire SQL world, the purpose of this is to provide the most basic and commonly used operations like CRUD (Create / Read / Update / Delete) to the database from the application, which I believe it covers 70% the simple data access operations in most applications.

Continuing the spirit of original library, this library can be used to help you generate the query and parameters that you can use in ADO.Net with SqlCommand or you can use with Dapper to have a simple mapping back to your entities.

Huge thanks and credits to the original author DomanyDusan and his tool. And I hope you guys, the developers, find my modified library helpful for your works/projects. All feedbacks and suggestions are welcome so that I can make this tool better.

Installation

Install using Package Reference

dotnet add [YOUR_PROJECT_NAME] package DotNetBrightener.LinQToSqlBuilder

You can optionally specified version by using --version [version] parameter

Usage

Simple Select

This basic example queries the database for 10 User and order them by their registration date using Dapper:

var query = SqlBuilder.Select<User>()
                      .OrderBy(_ => _.RegistrationDate)
                      .Take(10);
                      
var results = Connection.Query<User>(query.CommandText, query.CommandParameters);

As you can see the CommandText property will return the SQL string itself, while the CommandParameters property refers to a dictionary of SQL parameters.

Select query with Join

The below example performs a query to the User table, and join it with UserGroup table to returns a many to many relationship mapping specified using Dapper mapping API

var query = SqlBuilder.Select<User>()
                    //.Where(user => user.Email == email)
                      .Join<UserUserGroup>((@user, @group) => user.Id == group.UserId)
                      .Join<UserGroup>((group,     g) => group.UserGroupId == g.Id)
                      .Where(group => group.Id == groupId);

var result = new Dictionary<long, User>();
var results = Connection.Query<User, UserGroup, User>(query.CommandText,
                                                        (user, group) =>
                                                        {
                                                            if (!result.ContainsKey(user.Id))
                                                            {
                                                                user.Groups = new List<UserGroup>();
                                                                result.Add(user.Id, user);
                                                            }

                                                            result[user.Id].Groups.Add(group);
                                                            return user;
                                                        },
                                                        query.CommandParameters,
                                                        splitOn: "UserId,UserGroupId")
                        .ToList();

Insert single record

The example below will generate an insert command with one record.

var query = SqlBuilder.Insert<UserGroup>(_ => new UserGroup
            {
                CreatedBy   = "TestSystem",
                CreatedDate = DateTimeOffset.Now,
                Description = "Created from Test System",
                Name        = "TestUserGroup",
                IsDeleted   = false
            });

var results = Connection.Execute(query.CommandText, query.CommandParameters);

Insert multiple records

The example below will generate an insert command with multiple records.

var query = SqlBuilder.InsertMany<UserGroup>(_ => new []
            {
                new UserGroup
                {
                    CreatedBy   = "TestSystem",
                    CreatedDate = DateTimeOffset.Now,
                    Description = "Created from Test System",
                    Name        = "TestUserGroup",
                    IsDeleted   = false
                },

                new UserGroup
                {
                    CreatedBy   = "TestSystem",
                    CreatedDate = DateTimeOffset.Now,
                    Description = "Created from Test System",
                    Name        = "TestUserGroup2",
                    IsDeleted   = false
                },

                new UserGroup
                {
                    CreatedBy   = "TestSystem",
                    CreatedDate = DateTimeOffset.Now,
                    Description = "Created from Test System",
                    Name        = "TestUserGroup3",
                    IsDeleted   = false
                }
            });

var results = Connection.Execute(query.CommandText, query.CommandParameters);

Insert by copying from another table

Sometimes we need to copy a bunch of records from one table to another. For instance, if we have an order that contains few products, and the quantity of the products are being updated before the order gets finalized. So we need to keep the inventory history records of all products that are being updated from time to time. Using Entity Framework, we could have loaded all inventory records of the specified products, then create a copied object and insert them to the inventory history. The more products you have, the slower performance you will suffer because you will have to deal with the data that are in memory versus the data that are being processed by other request(s).

var query = SqlBuilder.InsertFrom<Inventory, InventoryHistory>(inventory => new InventoryHistory()
                                   {
                                       CreatedBy        = "Cloning System",
                                       CreatedDate      = DateTimeOffset.Now,
                                       StockQuantity    = inventory.StockQuantity,
                                       ReservedQuantity = inventory.ReservedQuantity,
                                       IsDeleted        = inventory.IsDeleted,
                                       InventoryId      = inventory.Id,
                                       ProductId        = inventory.ProductId
                                   })
                                  .WhereIsIn(inventory => inventory.ProductId, new long[] { /*... obmited values, describes the list of product ids */ });

Assert.AreEqual("INSERT INTO [dbo].[InventoryHistory] ([CreatedBy], [CreatedDate], [StockQuantity], [ReservedQuantity], [IsDeleted], [InventoryId], [ProductId]) " +
                "SELECT " +
                "@Param1 as [CreatedBy], " +
                "@Param2 as [CreatedDate], " +
                "[dbo].[Inventory].[StockQuantity] as [StockQuantity], " +
                "[dbo].[Inventory].[ReservedQuantity] as [ReservedQuantity], " +
                "[dbo].[Inventory].[IsDeleted] as [IsDeleted], " +
                "[dbo].[Inventory].[Id] as [InventoryId] " +
                "[dbo].[Inventory].[ProductId] as [ProductId] " +
                "FROM [dbo].[Inventory] " +
                "WHERE [dbo].[Inventory].[ProductId] IS IN @Param3",
                query.CommandText);

Update a record

The example below will generate a command to update the User table, provides 3 properties to be updated, where user.Id equals the given value userId

var query = SqlBuilder.Update<User>(_ => new User
                                   {
                                       Email              = _.Email.Replace("@domain1.com", "@domain2.com"),
                                       LastChangePassword = DateTimeOffset.Now,
                                       FailedLogIns       = _.FailedLogIns + 1
                                   })
                    .Where(user => user.Id == userId);

var result = Connection.Execute(query.CommandText, query.CommandParameters);
// this will return the affected rows of the query

Delete a record / multiple records by condition

The example below will generate a command to delete from User table where the user.Email equals the specified userEmail value:

string userEmail = "query_email@domain1.com";

var query = SqlBuilder.Delete<User>()
                    .Where(user => user.Email == userEmail);
                    // .Where(user => user.Email.Contains("part_of_email_to_search"));

var result = Connection.Execute(query.CommandText, query.CommandParameters);

Reference

https://github.com/DomanyDusan/lambda-sql-builder

https://github.com/mladenb/sql-query-builder