How to map exisiting sql server view with EF code first

Question

i am fairly new in EF and learning EF code first. i am looking for a knowledge to map exisiting sql server view with EF code first. i have map my view with POCO but getting

Answer 1

Configure view as table and use this custom generator to prevent migration generation for tables marked as views

public class SkipViewGeneration : CSharpMigrationCodeGenerator
{
    protected override void Generate(CreateTableOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    protected override void Generate(RenameTableOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    protected override void Generate(MoveTableOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    protected override void Generate(DropTableOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    protected override void Generate(AddColumnOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Table))
            base.Generate(operation, writer);
    }

    protected override void Generate(DropColumnOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Table))
            base.Generate(operation, writer);
    }

    protected override void Generate(DropPrimaryKeyOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Table))
            base.Generate(operation, writer);
    }

    protected override void Generate(AlterColumnOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Table))
            base.Generate(operation, writer);
    }

    protected override void Generate(AddPrimaryKeyOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Table))
            base.Generate(operation, writer);
    }

    protected override void Generate(AlterTableOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    protected override void Generate(CreateIndexOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    protected override void Generate(DropIndexOperation operation, IndentedTextWriter writer)
    {
        if (!IsView(operation.Name))
            base.Generate(operation, writer);
    }

    private bool IsView(string tableNameWithSchemaName)
    {
        var tableName = DatabaseName.Parse(tableNameWithSchemaName).Name;
        var schemaName = DatabaseName.Parse(tableNameWithSchemaName).Schema;
        return schemaName.Contains("View");
    }
}

Usage example

internal sealed class Configuration : DbMigrationsConfiguration<AVMSDbContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
        CodeGenerator = new SkipViewGeneration();
    }

    protected override void Seed(AVMSDbContext context)
    {
        //  This method will be called after migrating to the latest version.

        //  You can use the DbSet<T>.AddOrUpdate() helper extension method
        //  to avoid creating duplicate seed data.
    }
}

DatabaseName.Parse implementatnion you can get from Github sources

Answer 2

OP's Feedback :

When i generate the view with ADO.Net Entity model wizard then everything works fine.

You can do it as shown below.

Note : I have picked the 1 to 4 from this post.

1. Create a POCO class for the view; for example FooView
2. Add the DbSet property in the DbContext class

3. Use a FooViewConfiguration file to set a different name for the view (using ToTable("Foo"); in the constructor) or to set particular properties

   public class FooViewConfiguration : EntityTypeConfiguration<FooView>      
   {
      public FooViewConfiguration()
      {
       this.HasKey(t => t.Id);
       this.ToTable("myView");
     }
   

   }

4. Add the FooViewConfiguration file to the modelBuilder, for example ovveriding the OnModelCreating method of the Context:

   protected override void OnModelCreating(DbModelBuilder modelBuilder)
   {
       modelBuilder.Configurations.Add(new FooViewConfiguration ());
   }
   

5. According to the above configuration,now your table is this.ToTable("myView");.In other words myView.

   Here is the EF query to retrieve all the data on the myView table.

   var listMyViews = yourDbContext.myView.ToList()

Your projection may be like this :

var query = yourDbContext.myView
        .Select(v=> new
        {
            ID = v.ID,
            EmpName = v.EmpName,
            Salary = v.Salary 
        }).ToList();