Introduction

Having tried ado.net, dapper, ef, and the Repository pattern, and even writing my own generator tools for common CRUD operations, I've encountered some inconveniences:

• Each time before use, it needs to be declared and then operated on.
• Many people have one operation class (or DAL, DbContext, Repository) for each entity class.

This document introduces a minimalist CRUD operation approach using BaseEntity.

Features

• Automatic migration of entity structure (CodeFirst) to the database.
• Direct CRUD operations using entity methods.
• Simplified entity type definition, eliminating the need to configure primary keys and common fields (such as CreateTime, UpdateTime).
• Implements soft delete logic for single-table and multi-table queries.

Declaration

Refer to the BaseEntity.cs source code (about 100 lines), copy it into your project, and then add the NuGet packages:

dotnet add package FreeSql.DbContext

dotnet add package FreeSql.Provider.Sqlite

1. Define an entity type with an int primary key that is auto-incremented. When BaseEntity<TKey> is specified as int/long, it will assume the primary key is auto-incremented:

public class UserGroup : BaseEntity<UserGroup, int> {
    public string GroupName { get; set; }
}

If you do not want the primary key to be auto-incremented, you can override the property:

public class UserGroup : BaseEntity<UserGroup, int> {
    [Column(IsIdentity = false)]
    public override int Id { get; set; }
    public string GroupName { get; set; }
}

For more entity attribute configurations, see Entity Attributes

2. Define an entity type with a Guid primary key. The Guid value will be automatically generated and ordered, so you don't need to specify Guid.NewGuid() yourself:

public class User : BaseEntity<UserGroup, Guid> {
    public string UserName { get; set; }
}

3. Define an entity type with multiple primary keys. You can override the field names in the static constructor:

public class User2 : BaseEntity<User2, Guid, int> {
    static User2()
    {
        User2.Orm.CodeFirst.ConfigEntity<User2>(t =>
        {
            t.Property(a => a.PkId1).Name("UserId");
            t.Property(a => a.PkId2).Name("Index");
        });
    }

    public string Username { get; set; }
}

CRUD Operations

// Add
var item = new UserGroup { GroupName = "Group One" };
item.Insert();

// Update
item.GroupName = "Group Two";
item.Update();

// Add or Update
item.Save();

// Soft Delete
item.Delete();

// Restore Soft Deleted
item.Restore();

// Get object by primary key
var item = UserGroup.Find(1);

// Query Data
var items = UserGroup.Where(a => a.Id > 10).ToList();

EntityType.Select is a query object and operates similarly to FreeSql.ISelect.

When performing multi-table queries, the soft delete condition will be appended to each table.

For more query methods, refer to Queries

Example project: https://github.com/dotnetcore/FreeSql/tree/master/Examples/base_entity