A package that mimics EF core actions with dapper. Used for the programmers that are not allowed to use EF core at their company
$ dotnet add package CustomDapperEntityActionsA .NET package that provides Entity Framework Core-like actions using Dapper, designed for developers whose companies restrict the use of EF Core.
CustomDapperEntityActions bridges the gap between Dapper's lightweight performance and Entity Framework Core's convenient entity management features. It offers familiar entity action patterns while maintaining Dapper's speed and flexibility.
Install via NuGet Package Manager: dotnet add package CustomDapperEntityActions --version 1.0.6
Link to nuget: https://www.nuget.org/packages/CustomDapperEntityActions/
[Table("[schema].[table]")]
public class Plant
{
[Key]
[Column("id")]
public int Id { get; set; }
[Column("description")]
public string? Description { get; set; }
[Column("is_active")]
public bool IsAcive { get; set; }
}
1.1 Define Entities with 1..n relationship
// Parent table
[Table("parent")]
public class Parent
{
[Key]
[Column("parent_id")]
public int ParentId { get; set; }
[Column("name")]
public required string Name { get; set; }
[NotMapped]
public List<Child> Children { get; set; } = new List<Child>(); // initialise is important and needed
}
// Child table
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;
[Table("child")]
public class Child
{
[Key]
[Column("child_id")]
public int ChildId { get; set; }
// foreign key to parent necessary
[Column("parent_id")]
[ForeignKey("Parent")]
public int ParentId { get; set; }
[Column("name")]
public required string Name { get; set; }
[Column("is_active")]
public bool IsActive { get; set; }
}
public class ApplicationDbContext : IDisposable
{
// if using postgres, sql also possible
private readonly NpgsqlConnection _connection;
private IDbTransaction _transaction;
// Expose the connection for custom transaction management
public IDbConnection Connection => _connection;
// Expose the current transaction
public IDbTransaction Transaction => _transaction;
// The entity we just made
public DapperSet<Plant> Plants { get; }
public ApplicationDbContext(string connectionString)
{
_connection = new NpgsqlConnection(connectionString);
_connection.Open();
_transaction = _connection.BeginTransaction();
// assign them
Plants = new DapperSet<Plant>(_connection, _transaction);
}
public void Commit() => _transaction?.Commit();
public void Rollback() => _transaction?.Rollback();
public void Dispose()
{
_transaction?.Dispose();
_connection?.Dispose();
}
}
bld.Services.AddScoped<ApplicationDbContext>(provider => new ApplicationDbContext(connectionString));// insert
var insert = await dbContext.Tests.InsertAsync<string>(new TestLalala
{
Description = "Test",
IsAcive = true
});
// update
var update = await dbContext.Tests.UpdateAsync(new TestLalala
{
Id = 5,
Description = "Luksass",
IsAcive = true
});
// Get byid
await dbContext.Tests.GetByIdAsync(5);
await dbContext.Tests.DeleteAsync(5);
// IMPORTANT: You must call Commit() to persist changes to the database
// after Insert, Update, or Delete operations
dbContext.Commit();
// Linq like query NEW version
var specificTests = await dbContext.Tests
.Where(x => x.TestCd == "Zoko")
.OrderBy(x => x.Description)
.ExecuteAsync();
// without where also possible
var specificTests = await dbContext.Tests
.OrderBy(x => x.Description)
.ExecuteAsync();
// only where also possible
var specificTests = await dbContext.Tests
.Where(x => x.TestCd == "Zoko")
// descending
var specificTests = await dbContext.Tests
.OrderBy(x => x.Description, descending: true)
.ExecuteAsync();
// Chaining statements
var specificTests = await dbContext.Tests
.Where( x => x.TestMode == "Offline")
.Where(x => x.IsActive )
.OrderBy(x => x.TestType)
.OrderBy( x => x.TestMode)
.ExecuteAsync();
// Linq like query OLD version
var specificTests = await dbContext.Tests.WhereAsync(x =>x.IsAcive );
// GetAll
DbContext.Tests.GetAllAsync
When using Insert, Update, or Delete operations, you must call dbContext.Commit() to persist your changes to the database:
// Insert a new entity
await dbContext.Plants.InsertAsync<string>(new Plant {
PlantCd = "PLANT5",
Description = "New Plant",
IsAcive = true
});
// Update an existing entity
await dbContext.Plants.UpdateAsync(new Plant {
PlantCd = "PLANT5",
Description = "Updated Plant",
IsAcive = false
});
// Delete an entity
await dbContext.Plants.DeleteAsync<string>("PLANT5");
// Commit the transaction to persist all changes
dbContext.Commit();
// If you need to rollback changes instead
// dbContext.Rollback();The library uses transactions to ensure data consistency. Without calling Commit(), your changes will be rolled back when the DbContext is disposed.
The library supports two ways to manage transactions:
Default Transaction: By default, all operations use the transaction provided in the DbContext constructor.
Custom Transaction: You can now provide a specific transaction to individual CRUD operations, which will override the default transaction.
Each CRUD method (ExecuteAsync, InsertAsync, UpdateAsync, and DeleteAsync) accepts an optional transaction parameter:
// Using the default transaction from DbContext
await dbContext.Plants.InsertAsync<string>(newPlant);
// Using a custom transaction
using var customTransaction = dbContext.Connection.BeginTransaction();
await dbContext.Plants.InsertAsync<string>(newPlant, customTransaction);
customTransaction.Commit();
// Multiple operations within the same custom transaction
using var transaction = dbContext.Connection.BeginTransaction();
await dbContext.Plants.InsertAsync<string>(newPlant, transaction);
await dbContext.Tests.UpdateAsync(existingTest, transaction);
await dbContext.Measurements.DeleteAsync<int>(measurementId, transaction);
transaction.Commit();This feature is useful when you need to:
var specificTests = await dbContext.Tests
// Other linq queries
.Paginate(0,50) // paginate(pageIndex, pageSize), this gives records 0-50
.ExecuteAsync();The Select feature allows you to project entities to a different type, similar to Entity Framework Core's Select method. This optimizes your queries by only retrieving the columns you need from the database.
// Select specific properties
var descriptions = await dbContext.Plants
.Select(p => p.Description)
.ExecuteAsync();
// Project to an anonymous type
var plantInfo = await dbContext.Plants
.Select(p => new { p.PlantCd, p.Description })
.ExecuteAsync();
// Combine with Where (filtering happens at the database level)
var activePlants = await dbContext.Plants
.Select(p => new { p.PlantCd, p.Description })
.Where(p => p.IsAcive)
.ExecuteAsync();
// Combine with OrderBy
var orderedPlants = await dbContext.Plants
.Select(p => new { p.PlantCd, p.Description })
.OrderBy(p => p.Description)
.ExecuteAsync();
// Combine with Paginate
var pagedPlants = await dbContext.Plants
.Select(p => new { p.PlantCd, p.Description })
.Paginate(0, 10)
.ExecuteAsync();The Select method modifies the SQL SELECT statement to only include the specified columns, which is more efficient than retrieving all columns. It also supports filtering on properties that are not included in the Select projection, with the filtering happening at the database level.
If you want to log the queries, you need to put miminum log level to "Information" and use serilog.
Joins can be done with the include tag (only one to one mapping currently one to many is for future features )
var measurements = await dbContext.Measurements
.Include(x => x.Test)
.Include(x => x.Plant)
// then you can also filter only on the parent
.Where(x => x.Value > 100)
.OrderBy(x => x.MeasurementDate)
.Paginate(0, 2)
.ExecuteAsync();Interceptors provide a powerful way to hook into the entity lifecycle, allowing you to execute custom logic before or after insert and update operations. This feature gives you complete control over what happens at these critical points.
// Create a DbContext with interceptors
public class ApplicationDbContext : IDisposable
{
private readonly NpgsqlConnection _connection;
private IDbTransaction _transaction;
public DapperSet<TestLalala> Tests { get; }
public ApplicationDbContext(string connectionString)
{
_connection = new NpgsqlConnection(connectionString);
_connection.Open();
_transaction = _connection.BeginTransaction();
// Create your custom interceptor
var yourInterceptor = new YourCustomInterceptor();
// Use the interceptor with a DapperSet
Tests = new DapperSet<TestLalala>(_connection, _transaction, yourInterceptor);
}
// ... Commit, Rollback, Dispose methods
}You can create interceptors by implementing ISaveChangesInterceptor or extending the SaveChangesInterceptor base class. This gives you complete freedom to decide what happens before or after insert/update operations:
public class YourCustomInterceptor : SaveChangesInterceptor
{
// Called before an entity is inserted
public override Task BeforeInsertAsync(object entity, CancellationToken cancellationToken = default)
{
// Your custom logic here
if (entity is TestLalala test)
{
// For example, set creation date
test.CreatedDate = DateTime.UtcNow;
}
return Task.CompletedTask;
}
// Called after an entity is inserted
public override Task AfterInsertAsync(object entity, CancellationToken cancellationToken = default)
{
// Post-insert logic here
return Task.CompletedTask;
}
// Called before an entity is updated
public override Task BeforeUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
// Your custom update logic here
if (entity is TestLalala test)
{
// For example, set last edit date
test.LastEditDate = DateTime.UtcNow;
}
return Task.CompletedTask;
}
// Called after an entity is updated
public override Task AfterUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
// Post-update logic here
return Task.CompletedTask;
}
}Here's an example of an interceptor that handles both creation and modification dates:
public class AuditInterceptor : SaveChangesInterceptor
{
public override Task BeforeInsertAsync(object entity, CancellationToken cancellationToken = default)
{
if (entity is TestLalala test)
{
// Set creation date on insert
test.CreatedDate = DateTime.UtcNow;
// Initialize last edit date to same value
test.LastEditDate = test.CreatedDate;
}
return Task.CompletedTask;
}
public override Task BeforeUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
if (entity is TestLalala test)
{
// Only update the last edit date, not the creation date
test.LastEditDate = DateTime.UtcNow;
}
return Task.CompletedTask;
}
}You can use multiple interceptors together, and they will be executed in the order they are provided:
// Create multiple interceptors
var auditInterceptor = new AuditInterceptor();
var validationInterceptor = new ValidationInterceptor();
var loggingInterceptor = new LoggingInterceptor();
// Use them together
var entitySet = new DapperSet<TestLalala>(
_connection,
_transaction,
auditInterceptor, // Executed first
validationInterceptor, // Executed second
loggingInterceptor // Executed third
);public class ValidationInterceptor : SaveChangesInterceptor
{
public override Task BeforeInsertAsync(object entity, CancellationToken cancellationToken = default)
{
ValidateEntity(entity);
return Task.CompletedTask;
}
public override Task BeforeUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
ValidateEntity(entity);
return Task.CompletedTask;
}
private void ValidateEntity(object entity)
{
if (entity is TestLalala test)
{
// Perform validation
if (string.IsNullOrEmpty(test.Description))
{
throw new ArgumentException("Description cannot be empty");
}
if (test.Precision < 0 || test.Precision > 100)
{
throw new ArgumentException("Precision must be between 0 and 100");
}
}
}
}public class LoggingInterceptor : SaveChangesInterceptor
{
private readonly ILogger _logger;
public LoggingInterceptor(ILogger logger)
{
_logger = logger;
}
public override Task BeforeInsertAsync(object entity, CancellationToken cancellationToken = default)
{
_logger.LogInformation($"Inserting entity of type {entity.GetType().Name}");
return Task.CompletedTask;
}
public override Task AfterInsertAsync(object entity, CancellationToken cancellationToken = default)
{
_logger.LogInformation($"Successfully inserted entity of type {entity.GetType().Name}");
return Task.CompletedTask;
}
public override Task BeforeUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
_logger.LogInformation($"Updating entity of type {entity.GetType().Name}");
return Task.CompletedTask;
}
public override Task AfterUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
_logger.LogInformation($"Successfully updated entity of type {entity.GetType().Name}");
return Task.CompletedTask;
}
}This advanced interceptor tracks which user created or last modified an entity, providing accountability in multi-user systems:
public class UserTrackingInterceptor : SaveChangesInterceptor
{
// Current user context
public string CurrentUser { get; set; }
public string CurrentRole { get; set; }
public UserTrackingInterceptor(string initialUser, string initialRole)
{
CurrentUser = initialUser;
CurrentRole = initialRole;
}
public override Task BeforeInsertAsync(object entity, CancellationToken cancellationToken = default)
{
if (entity is IUserTrackable trackable)
{
// Set both created and last edited fields on insert
trackable.CreatedBy = CurrentUser;
trackable.CreatedRole = CurrentRole;
trackable.LastEditedBy = CurrentUser;
trackable.LastEditedRole = CurrentRole;
}
return Task.CompletedTask;
}
public override Task BeforeUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
if (entity is IUserTrackable trackable)
{
// Only update the last edited fields, preserve creation info
trackable.LastEditedBy = CurrentUser;
trackable.LastEditedRole = CurrentRole;
}
return Task.CompletedTask;
}
}
// Interface for trackable entities
public interface IUserTrackable
{
string CreatedBy { get; set; }
string CreatedRole { get; set; }
string LastEditedBy { get; set; }
string LastEditedRole { get; set; }
}
// Example entity implementing the interface
public class UserTrackableEntity : IUserTrackable
{
[Key]
[Column("id")]
public int Id { get; set; }
[Column("name")]
public string Name { get; set; }
[Column("created_by")]
public string CreatedBy { get; set; }
[Column("created_role")]
public string CreatedRole { get; set; }
[Column("last_edited_by")]
public string LastEditedBy { get; set; }
[Column("last_edited_role")]
public string LastEditedRole { get; set; }
}This interceptor automatically manages version numbers for entities, which is useful for optimistic concurrency and tracking changes:
public class VersioningInterceptor : SaveChangesInterceptor
{
public override Task BeforeInsertAsync(object entity, CancellationToken cancellationToken = default)
{
if (entity is IVersionable versionable)
{
// Start at version 1 for new entities
versionable.Version = 1;
}
return Task.CompletedTask;
}
public override Task BeforeUpdateAsync(object entity, CancellationToken cancellationToken = default)
{
if (entity is IVersionable versionable)
{
// Increment version on each update
versionable.Version++;
}
return Task.CompletedTask;
}
}
// Interface for versionable entities
public interface IVersionable
{
int Version { get; set; }
}
// Example entity implementing the interface
public class VersionedEntity : IVersionable
{
[Key]
[Column("id")]
public int Id { get; set; }
[Column("name")]
public string Name { get; set; }
[Column("version")]
public int Version { get; set; }
}This example shows how to combine multiple interceptors to create a comprehensive entity lifecycle management system:
// Create a DbContext with multiple interceptors
public class ApplicationDbContext : IDisposable
{
private readonly NpgsqlConnection _connection;
private IDbTransaction _transaction;
public DapperSet<ComplexEntity> ComplexEntities { get; }
public ApplicationDbContext(string connectionString, string currentUser, string currentRole)
{
_connection = new NpgsqlConnection(connectionString);
_connection.Open();
_transaction = _connection.BeginTransaction();
// Create multiple interceptors
var auditInterceptor = new AuditInterceptor();
var userTrackingInterceptor = new UserTrackingInterceptor(currentUser, currentRole);
var versioningInterceptor = new VersioningInterceptor();
var validationInterceptor = new ValidationInterceptor();
// Use them together with a DapperSet
ComplexEntities = new DapperSet<ComplexEntity>(
_connection,
_transaction,
auditInterceptor, // Handles creation and modification dates
userTrackingInterceptor, // Tracks who created/modified the entity
versioningInterceptor, // Manages version numbers
validationInterceptor // Validates the entity before saving
);
}
// ... Commit, Rollback, Dispose methods
}
// A complex entity that implements multiple interfaces
public class ComplexEntity : IUserTrackable, IVersionable
{
[Key]
[Column("id")]
public int Id { get; set; }
[Column("name")]
public string Name { get; set; }
[Column("created_date")]
public DateTime CreatedDate { get; set; }
[Column("last_edit_date")]
public DateTime LastEditDate { get; set; }
[Column("created_by")]
public string CreatedBy { get; set; }
[Column("created_role")]
public string CreatedRole { get; set; }
[Column("last_edited_by")]
public string LastEditedBy { get; set; }
[Column("last_edited_role")]
public string LastEditedRole { get; set; }
[Column("version")]
public int Version { get; set; }
}This approach allows you to build a modular, maintainable system where each interceptor handles a specific concern, following the Single Responsibility Principle.
Classes need to be annotated like this with the NotMapped and ForeignKey tag
[Table("ipc.measurement")]
public class CoolMeasurement
{
[Key]
[Column("id")]
public int Id { get; set; }
[Column("test_cd")]
public required string TestCd { get; set; }
[Column("plant_cd")]
public required string PlantCd { get; set; }
[Column("avg_value")]
public double Value { get; set; }
[Column("measurement_date")]
public DateTime MeasurementDate { get; set; } = DateTime.UtcNow;
[NotMapped]
[ForeignKey("test_cd")]
public TestLalala Test { get; set; }
[NotMapped]
[ForeignKey("plant_cd")]
public Plant Plant { get; set; }
}