Visual Studio 2017中从数据库生成VB.NET类的工具及最优方法咨询

Hey there! Let’s dive into the best tools and smarter approaches for generating VB.NET classes that directly mirror your database tables—where each class maps to a table and every property lines up with a column.

Top Tools to Generate VB.NET Classes from Database Tables #

1. Visual Studio’s Built-in Entity Framework Reverse Engineering #

This is the easiest, no-additional-installation option since it’s baked right into VS2017:

• Right-click your VB.NET project → Add → New Item
• Under the Data category, select ADO.NET Entity Data Model
• Choose Code First from Database (or Database First if you prefer working with an EDMX file)
• Connect to your database, select the tables you want to generate classes for, and click Finish
• VS will auto-generate VB.NET classes for each table, with properties matching column names, data types, and nullability. You’ll also get a DbContext class to handle database interactions.

2. Entity Framework Core Scaffolding (Package Manager Console) #

If you prefer a more command-line approach with EF Core (lighter weight than EF6), use the Scaffold-DbContext command in the Package Manager Console:

Scaffold-DbContext "YourDatabaseConnectionString" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models -Language VB -Force

• Replace YourDatabaseConnectionString with your actual connection string
• -OutputDir Models puts all generated classes in a Models folder
• -Language VB ensures output is in VB.NET (default is C#, so this is crucial)
• -Force lets you overwrite existing classes if your database schema changes later

3. T4 Text Templates (Customizable Generation) #

For full control over the generated code (like adding comments, data annotations, or implementing interfaces), use T4 templates:

• Add a new Text Template (.tt file) to your project
• Write template code to query your database’s schema (via System.Data.SqlClient or metadata APIs)
• Loop through tables and columns to generate VB.NET class code dynamically
• This is great if you need consistent customizations across all your entity classes (e.g., adding INotifyPropertyChanged for WPF bindings)

Smarter Mapping Approaches Beyond Basic Generation #

Use Data Annotations or Fluent API for Precise Mapping #

Auto-generated classes work well out of the box, but you can refine mappings to handle edge cases:

• Data Annotations: Add attributes directly to properties to clarify mappings, e.g.:

  Public Class Customer
      <Key>
      Public Property CustomerID As Integer
  
      <Column("CustomerName")>
      Public Property Name As String
  
      <Required>
      Public Property Email As String
  End Class
  

• Fluent API: Configure mappings in your DbContext’s OnModelCreating method for more complex scenarios (like relationships, composite keys, or custom column types):

  Protected Overrides Sub OnModelCreating(modelBuilder As ModelBuilder)
      modelBuilder.Entity(Of Customer)() _
          .HasKey(c => c.CustomerID)
      modelBuilder.Entity(Of Customer)() _
          .Property(c => c.Name) _
          .HasColumnName("CustomerName")
  End Sub
  

Separate Entity Classes from Business Logic #

Keep your database-mapped classes clean by separating business logic into separate service classes. This way, your entity classes only handle data storage, and all business rules live elsewhere—making your code easier to maintain and test.

Handle Schema Updates Gracefully #

When your database schema changes:

• For EF6: Right-click your EDMX file → Update Model from Database to refresh classes
• For EF Core: Re-run the Scaffold-DbContext command with the -Force parameter to overwrite existing classes (just make sure you don’t lose custom changes—consider partial classes to add custom code without modifying auto-generated files)

内容的提问来源于stack exchange，提问作者Jonathan Roberts