DataLinq v0.5.1 Release Notes

This release primarily focuses on critical fixes related to object equality, collection handling, source generator compatibility, and internal refactoring for improved robustness. It addresses key issues identified after the major v0.5.0 release.

🚀 Highlights & Fixes:

• Corrected Object Equality (Equals & GetHashCode):
  • Breaking Change (Behavioral): The core equality comparison for entity instances (Immutable and Mutable) has been changed. Instead of comparing all property values, equality is now correctly based solely on the Primary Key(s). This aligns with standard ORM identity practices.
  • Two instances representing the same database row (same PK) will now be considered equal (instance1.Equals(instance2) returns true), regardless of whether other property values differ (e.g., due to one instance being stale).
  • GetHashCode() is now also based only on the Primary Key, ensuring stability, especially for mutable objects used in hash-based collections.
• Improved Handling of New/Unsaved Instances:
  • Mutable<T> instances created via new() (before being saved to the database and receiving a real Primary Key, especially auto-increments) now use an internal, temporary TransientId (a Guid) for Equals and GetHashCode.
  • This allows distinct new instances to be correctly differentiated and managed in collections (List, HashSet, Dictionary keys, GroupBy) before they are saved.
  • Important Note: As documented previously, the hash code of a mutable instance will change upon saving when it transitions from using the TransientId to using the database Primary Key. Avoid placing new instances in hash-based collections if you intend to save them later without removing/re-adding.
• Source Generator Compatibility:
  • Downgraded the required Microsoft.CodeAnalysis.CSharp package version from 4.13 to 4.12. This resolves runtime loading errors for users with slightly older (but still common) Visual Studio 2022 / .NET SDK versions, the minimum supported version is now Visual Studio 2022 version 17.12
  • Fixed a generator crash that occurred if only a database class was present without any table models.
• Internal Refinements & Cleanup:
  • Refactored relation handling internally for better encapsulation.
  • Removed remnants of unsupported ICustomTableModel implementation.
  • Improved internal error handling.
  • Cleaned up NuGet packaging configuration for clarity.

🐛 Other Bug Fixes:

• Resolved build/dependency issues in the source generator test project.

📝 Notes:

• This release addresses significant behavioral issues related to equality checks that could cause problems when using DataLinq entities in standard .NET collections or with LINQ operators like GroupBy. The new PK-based equality is the standard and correct approach for ORM entities.
• The generator compatibility fix ensures wider usability across common developer environments.

DataLinq v0.5.0 Release Notes

This release marks a significant step forward for DataLinq, switching to using a source generator instead of reflection, improving performance by reducing memory allocations, major internal refactorings for robustness, and adding foundational features like logging and improved error handling. I also made substantial progress on documentation, including a new DocFX-based website.

🚨 Breaking Changes:

• Target Frameworks Updated: DataLinq now targets .NET 8.0 and .NET 9.0. Support for .NET 6 and .NET 7 has been removed. Please update your projects accordingly.

🚀 Highlights:

• Major work on a new Source Generator: A new source generator to replace the old Castle.Core based code.
  • Generates two new classes Mutable[model] and Immutable[model].
  • Supports C# nullable reference types (#nullable enable).
  • Correctly generates required properties on mutable models based on database constraints and default values.
  • Generates code respecting [DefaultValue] attributes from your models.
  • Improved error reporting and internal structure (moved to DataLinq.Generators project).
  • Reliably generates interfaces (e.g., IEmployee) alongside model classes.
• Performance Boost & Reduced Allocations:
  • Introduced ReadOnlyAccess for significantly faster, lower-allocation reads compared to using a Transaction.
  • Optimized primary and foreign key handling using value type IKey structs (like IntKey, GuidKey, CompositeKey), reducing object allocations.
  • Improved performance for Count() and Any() LINQ operations.
  • Optimized relation loading with ImmutableRelation<T> and ImmutableForeignKey<T>.
• Logging Integration: Added basic logging using Microsoft.Extensions.Logging. SQL commands, cache events, and transaction information can now be logged.
• Enhanced Error Handling: Improved the internal DLOptionFailure system and exception messages for clearer diagnostics.
• Documentation Website: Introduced a documentation website generated using DocFX for easier navigation and access to information. (See project README for link when available).
• Default Value Support: Models generated from databases now include [DefaultValue] attributes, and the source generator respects these when creating mutable classes. SQL generation also handles default values.

✨ Features & Enhancements:

• Added provider-specific SQL identifier escaping (e.g., ` for MySQL, " for SQLite).
• Refined mutation and save method workflows.
• Improved handling of Nullable<T> types internally and in LINQ queries.

🛠 Refactoring & Internal Improvements:

• Significant refactoring of core metadata classes (DatabaseDefinition, TableDefinition, ModelDefinition, etc.) for improved immutability, clarity, and reduced internal nullability warnings.
• Refactored RowCache into its own class.
• Cleaned up build system using Directory.Build.props.
• Moved testing models to a dedicated DataLinq.Tests.Models project.

🐛 Bug Fixes:

• Fixed loading issues with nullable vs. non-nullable values.
• Fixed an issue where calling Update with no actual changes would cause an error.
• Fixed mutable classes being incorrectly generated for database Views.
• Fixed incorrect column length parsing for MySQL numeric types.
• Fixed issues with multiple foreign key relations pointing to the same table.
• Fixed LINQ query translation involving nullable booleans.
• Fixed loading of nullable DateOnly values.
• Addressed numerous nullability warnings throughout the codebase.
• Fixed preservation of original database model class names during generation/updates.
• Fixed various bugs related to SQLite compatibility (AutoIncrement, index types).

📦 Dependencies:

• Updated various NuGet package dependencies, including MySqlConnector, Microsoft.Data.Sqlite, Microsoft.CodeAnalysis, and testing libraries.

0.0.1 - Will probably eat your data

First release with basic functionality.

• Row cache
• Query builder
• Linq queries
• MySql support
• Database metadata
• Support for automatic creation of data models from database
• Working CRUD
• Transaction support
• Support for Select, Insert, Update, Delete, Where, Limit, OrderBy and nested And/Or
• Support for lazy loading of model properties