How to: Remove a table from the database

This article is relevant to entity models that utilize the deprecated Visual Studio integration of Telerik Data Access. The current documentation of the Data Access framework is available here.

This article will demonstrate to you how you can drop a given table that became obsolete from your database. Let's take a look at an example that uses SofiaCarRental and requires the RentalRates table to be removed.

1. Find the MetadataSource file of your fluent model in Solution Explorer and open it

   

2. In the PrepareMapping() method, locate the mapping configuration for the RentalRate class and mark it with the Drop() method before adding it in the list with the mapping configurations of the model

   In order to use the Drop() method you need to add a using / Imports clause to the Telerik.OpenAccess.Metadata.Fluent.Advanced namespace in your code.

   protected override IList<MappingConfiguration> PrepareMapping()
   {
       List<MappingConfiguration> mappingConfigurations = 
                      new List<MappingConfiguration>();
       MappingConfiguration<RentalRate> rentalrateConfiguration = 
                      this.GetRentalRateMappingConfiguration();
       rentalrateConfiguration.Drop();
       mappingConfigurations.Add(rentalrateConfiguration);
       //Mapping configurations for other types
       return mappingConfigurations;
   }
   public MappingConfiguration<RentalRate> GetRentalRateMappingConfiguration()
   {
       MappingConfiguration<RentalRate> configuration = 
              this.GetRentalRateClassConfiguration();
       this.PrepareRentalRatePropertyConfigurations(configuration);
       this.PrepareRentalRateAssociationConfigurations(configuration);
       return configuration;
   }
   public MappingConfiguration<RentalRate> GetRentalRateClassConfiguration()
   {
       MappingConfiguration<RentalRate> configuration = 
              new MappingConfiguration<RentalRate>();
       configuration.MapType(x => new { }).
                     WithConcurencyControl(OptimisticConcurrencyControlStrategy.Changed).
                     ToTable("RentalRates");
       return configuration;
   }
   public void PrepareRentalRatePropertyConfigurations(MappingConfiguration<RentalRate> configuration)
   {
       configuration.HasProperty(x => x.RentalRateID).IsIdentity(KeyGenerator.Autoinc).
                     HasFieldName("_rentalRateID").WithDataAccessKind(DataAccessKind.ReadWrite).
                     ToColumn("RentalRateID").IsNotNullable().HasColumnType("int").
                     HasPrecision(0).HasScale(0);
       configuration.HasProperty(x => x.CategoryID).HasFieldName("_categoryID").
                     WithDataAccessKind(DataAccessKind.ReadWrite).
                     ToColumn("CategoryID").IsNullable().HasColumnType("int").
                     HasPrecision(0).HasScale(0);
       configuration.HasProperty(x => x.Daily).HasFieldName("_daily").
                     WithDataAccessKind(DataAccessKind.ReadWrite).ToColumn("Daily").
                     IsNullable().HasColumnType("smallmoney").HasPrecision(0).HasScale(0);
       configuration.HasProperty(x => x.Weekly).HasFieldName("_weekly").
                     WithDataAccessKind(DataAccessKind.ReadWrite).ToColumn("Weekly").
                     IsNullable().HasColumnType("smallmoney").HasPrecision(0).HasScale(0);
       configuration.HasProperty(x => x.Monthly).HasFieldName("_monthly").
                     WithDataAccessKind(DataAccessKind.ReadWrite).ToColumn("Monthly").
                     IsNullable().HasColumnType("smallmoney").HasPrecision(0).HasScale(0);
   }
   public void PrepareRentalRateAssociationConfigurations(MappingConfiguration<RentalRate> configuration)
   {
       configuration.HasAssociation(x => x.Category).HasFieldName("_category").
                     WithOpposite(x => x.RentalRates).ToColumn("CategoryID").
                     HasConstraint((x, y) => x.CategoryID == y.CategoryID).
                     WithDataAccessKind(DataAccessKind.ReadWrite);
   }
   

   Protected Overrides Function PrepareMapping() As IList(Of MappingConfiguration)
       Dim mappingConfigurations As New List(Of MappingConfiguration)()
       Dim rentalrateConfiguration As MappingConfiguration(Of RentalRate) =_
                                   Me.GetRentalRateMappingConfiguration()
       rentalrateConfiguration.Drop()
       mappingConfigurations.Add(rentalrateConfiguration)
       'Mapping configurations for other types
       Return mappingConfigurations
   End Function
   Public Function GetRentalRateMappingConfiguration() As MappingConfiguration(Of RentalRate)
       Dim configuration As MappingConfiguration(Of RentalRate) =_
                         Me.GetRentalRateClassConfiguration()
       Me.PrepareRentalRatePropertyConfigurations(configuration)
       Me.PrepareRentalRateAssociationConfigurations(configuration)
       Return configuration
   End Function
   Public Function GetRentalRateClassConfiguration() As MappingConfiguration(Of RentalRate)
       Dim configuration As New MappingConfiguration(Of RentalRate)()
       configuration.MapType(Function(x) New With {x})._
                     WithConcurencyControl(OptimisticConcurrencyControlStrategy.Changed)._
                     ToTable("RentalRates")
       Return configuration
   End Function
   Public Sub PrepareRentalRatePropertyConfigurations(configuration As MappingConfiguration(Of RentalRate))
       configuration.HasProperty(Function(x) x.RentalRateID).IsIdentity(KeyGenerator.Autoinc)._
                     HasFieldName("_rentalRateID").WithDataAccessKind(DataAccessKind.ReadWrite)._
                     ToColumn("RentalRateID").IsNotNullable().HasColumnType("int")._
                     HasPrecision(0).HasScale(0)
       configuration.HasProperty(Function(x) x.CategoryID).HasFieldName("_categoryID")._
                     WithDataAccessKind(DataAccessKind.ReadWrite)._
                     ToColumn("CategoryID").IsNullable().HasColumnType("int")._
                     HasPrecision(0).HasScale(0)
       configuration.HasProperty(Function(x) x.Daily).HasFieldName("_daily")._
                     WithDataAccessKind(DataAccessKind.ReadWrite)._
                     ToColumn("Daily").IsNullable().HasColumnType("smallmoney")._
                     HasPrecision(0).HasScale(0)
       configuration.HasProperty(Function(x) x.Weekly).HasFieldName("_weekly")._
                     WithDataAccessKind(DataAccessKind.ReadWrite).ToColumn("Weekly")._
                     IsNullable().HasColumnType("smallmoney")._
                     HasPrecision(0).HasScale(0)
       configuration.HasProperty(Function(x) x.Monthly).HasFieldName("_monthly")._
                     WithDataAccessKind(DataAccessKind.ReadWrite)._
                     ToColumn("Monthly").IsNullable().HasColumnType("smallmoney")._
                     HasPrecision(0).HasScale(0)
   End Sub
   Public Sub PrepareRentalRateAssociationConfigurations(configuration As MappingConfiguration(Of RentalRate))
   configuration.HasAssociation(Function(x) x.Category).HasFieldName("_category")._
                 WithOpposite(Function(x) x.RentalRates).ToColumn("CategoryID")._
                 HasConstraint(Function(x, y)  x.CategoryID = y.CategoryID )._
                 WithDataAccessKind(DataAccessKind.ReadWrite)
   End Sub
   

3. Create/Migrate your database with the UpdateSchema() method

The script that will be generated with the properties of the SchemaUpdateProperties class set to false in the CreateUpdateDDLScript() method of UpdateSchema() would look like this one:

-- dropping table [RentalRates]
DROP TABLE [RentalRates]
go

Dropped Database Objects According to The Relationships of The Marked Table