Data migration fluent API

Inject a SchemaBuilder instance configured with DataTablePrefix in Data Migration classes inheriting from DataMigrationImpl

--HG--
branch : dev

src/Orchard.Tests/DataMigration/DataMigrationCommandsTests.cs

@@ -0,0 +1,38 @@
+using System.Data;
+using NUnit.Framework;
+using Orchard.DataMigration.Schema;
+
+namespace Orchard.Tests.DataMigration {
+    [TestFixture]
+    public class DataMigrationCommandsTests {
+
+        [Test]
+        public void AllMethodsShouldBeCalledSuccessfully() {
+            var schemaBuilder = new SchemaBuilder("TEST_");
+
+            schemaBuilder
+                .CreateTable("User", table => table
+                    .ContentPartRecord()
+                    .Column("Id", DbType.Int32, column => column.PrimaryKey())
+                    .Column("Firstname", DbType.String, column => column.Length(255))
+                    .Column("Lastname", DbType.String, column => column.Precision(0).Scale(1))
+                    .ForeignKey("User_Address", fk => fk.On("Id", "Address", "UserId")))
+                .CreateTable("Address", table => table
+                    .VersionedContentPartRecord()
+                    .Column("City", DbType.String)
+                    .Column("ZIP", DbType.Int32, column => column.Unique())
+                    .Column("UserId", DbType.Int32, column => column.NotNull()))
+                .AlterTable("User", table => table
+                    .AddColumn("Age", DbType.Int32)
+                    .AlterColumn("Lastname", column => column.Default("John"))
+                    .AlterColumn("Lastname", column => column.Rename("John"))
+                    .DropColumn("Lastname")
+                    .CreateIndex("IDX_XYZ", "NickName")
+                    .DropIndex("IDX_XYZ")
+                    .AddForeignKey("FKL", fk => fk.On("Id", "A", "Id").On("Id", "B", "Id") )
+                    .DropForeignKey("FKL"))
+                .DropTable("Address")
+                .ExecuteSql("DROP DATABASE", statement => statement.ForDialect("SQLite").ForDialect("MsSqlServer2008"));
+        }
+    }
+}

src/Orchard.Tests/DataMigration/DataMigrationTests.cs

@@ -2,10 +2,12 @@
 using System.Collections.Generic;
 using System.Linq;
 using Autofac;
+using Moq;
 using NHibernate;
 using NUnit.Framework;
 using Orchard.ContentManagement.Records;
 using Orchard.Data;
+using Orchard.Environment.Configuration;
 using Orchard.Environment.Extensions;
 using Orchard.Environment.Extensions.Folders;
 using Orchard.Environment.Extensions.Loaders;
@@ -42,6 +44,9 @@ namespace Orchard.Tests.DataMigration {
 
             var builder = new ContainerBuilder();
             _folders = new StubFolders();
+            
+            builder.RegisterInstance(new ShellSettings { DataTablePrefix = "TEST_"});
+
             builder.RegisterInstance(_folders).As<IExtensionFolders>();
             builder.RegisterType<ExtensionManager>().As<IExtensionManager>();
             builder.RegisterType<DataMigrationManager>().As<IDataMigrationManager>();
@@ -149,6 +154,17 @@ namespace Orchard.Tests.DataMigration {
             }
         }
 
+        public class DataMigrationWithSchemaBuilder : DataMigrationImpl {
+            public override string Feature {
+                get { return "Feature1"; }
+            }
+
+            public int Create() {
+                Assert.That(SchemaBuilder, Is.Not.Null);
+                Assert.That(SchemaBuilder.TablePrefix, Is.EqualTo("TEST_"));
+                return 1;
+            }
+        }
         [Test]
         public void DataMigrationShouldDoNothingIfNoDataMigrationIsProvidedForFeature() {
             Init(new Type[] {typeof (DataMigrationEmpty)});
@@ -162,7 +178,7 @@ features:
     Description: Feature
 ");
 
-            _dataMigrationManager.Upgrade("Feature1");
+            _dataMigrationManager.Update("Feature1");
             Assert.That(_repository.Table.Count(), Is.EqualTo(0));
         }
 
@@ -179,7 +195,7 @@ features:
     Description: Feature
 ");
             
-            _dataMigrationManager.Upgrade("Feature1");
+            _dataMigrationManager.Update("Feature1");
             Assert.That(_repository.Table.Count(), Is.EqualTo(0));
         }
 
@@ -196,7 +212,7 @@ features:
     Description: Feature
 ");
             
-            _dataMigrationManager.Upgrade("Feature1");
+            _dataMigrationManager.Update("Feature1");
             Assert.That(_repository.Table.Count(), Is.EqualTo(1));
             Assert.That(_repository.Table.First().Current, Is.EqualTo(999));
             Assert.That(_repository.Table.First().DataMigrationClass, Is.EqualTo("Orchard.Tests.DataMigration.DataMigrationTests+DataMigration11Create"));
@@ -215,7 +231,7 @@ features:
     Description: Feature
 ");
             
-            _dataMigrationManager.Upgrade("Feature1");
+            _dataMigrationManager.Update("Feature1");
             Assert.That(_repository.Table.Count(), Is.EqualTo(1));
             Assert.That(_repository.Table.First().Current, Is.EqualTo(666));
         }
@@ -237,7 +253,7 @@ features:
                 DataMigrationClass = "Orchard.Tests.DataMigration.DataMigrationTests+DataMigrationSameMigrationClassCanEvolve"
             });
 
-            _dataMigrationManager.Upgrade("Feature1");
+            _dataMigrationManager.Update("Feature1");
             Assert.That(_repository.Table.Count(), Is.EqualTo(1));
             Assert.That(_repository.Table.First().Current, Is.EqualTo(999));
         }
@@ -265,12 +281,28 @@ features:
   Feature2: 
     Description: Feature
 ");
-            _dataMigrationManager.Upgrade("Feature1");
+            _dataMigrationManager.Update("Feature1");
             Assert.That(_repository.Table.Count(), Is.EqualTo(2));
             Assert.That(_repository.Fetch(d => d.Current == 999).Count(), Is.EqualTo(2));
             Assert.That(_repository.Fetch(d => d.DataMigrationClass == "Orchard.Tests.DataMigration.DataMigrationTests+DataMigrationDependenciesModule1").Count(), Is.EqualTo(1));
             Assert.That(_repository.Fetch(d => d.DataMigrationClass == "Orchard.Tests.DataMigration.DataMigrationTests+DataMigrationDependenciesModule2").Count(), Is.EqualTo(1));
         }
 
+        [Test]
+        public void DataMigrationImplShouldGetASchemaBuilder() {
+            Init(new Type[] { typeof(DataMigrationWithSchemaBuilder) });
+
+            _folders.Manifests.Add("Module1", @"
+name: Module1
+version: 0.1
+orchardversion: 1
+features:
+  Feature1: 
+    Description: Feature
+");
+
+            _dataMigrationManager.Update("Feature1");
+            Assert.That(_repository.Table.Count(), Is.EqualTo(1));
+        }
     }
 }

src/Orchard.Tests/Orchard.Framework.Tests.csproj

@@ -180,6 +180,7 @@
     <Compile Include="ContentManagement\Records\GammaRecord.cs">
       <SubType>Code</SubType>
     </Compile>
+    <Compile Include="DataMigration\DataMigrationCommandsTests.cs" />
     <Compile Include="DataMigration\DataMigrationTests.cs" />
     <Compile Include="DataUtility.cs" />
     <Compile Include="Data\Builders\SessionFactoryBuilderTests.cs" />

src/Orchard/DataMigration/Commands/DataMigrationCommands.cs

@@ -18,7 +18,7 @@ namespace Orchard.DataMigration.Commands {
         [OrchardSwitches("Feature")]
         public string UpgradeDatabase() {
             try {
-                _dataMigrationManager.Upgrade(Feature);
+                _dataMigrationManager.Update(Feature);
             }
             catch ( Exception ex ) {
                 Context.Output.WriteLine(T("An error occured while upgrading the database: " + ex.Message));

src/Orchard/DataMigration/DataMigration.cs

@@ -1,5 +1,11 @@
-namespace Orchard.DataMigration {
-    public abstract class DataMigration : IDataMigration {
+using Orchard.DataMigration.Schema;
+
+namespace Orchard.DataMigration {
+    /// <summary>
+    /// Data Migration classes can inherit from this class to get a SchemaBuilder instance configured with the current tenant database prefix
+    /// </summary>
+    public abstract class DataMigrationImpl : IDataMigration {
         public abstract string Feature { get; }
+        public SchemaBuilder SchemaBuilder { get; set; }
     }
 }

src/Orchard/DataMigration/DataMigrationCoordinator.cs

@@ -0,0 +1,40 @@
+using Orchard.Environment;
+using Orchard.Environment.Extensions.Models;
+
+namespace Orchard.DataMigration {
+    /// <summary>
+    /// Responsible for executing data migration tasks when a feature is enabled for the first time
+    /// 1) Initial install of a module:
+    ///     Enable a feature for the first time => run data migration up to the latest version
+    ///     Enable a feature on 2nd time => no data migration run
+    ///     Disable a feature => no data migration
+    /// 2) Installing a newer version of a module
+    /// Don't do any data migration by default
+    /// 2 cases: 
+    ///     1) feature wasn't not enabled when new code was installed
+    ///     2) feature was enabled when new code was installed
+    /// </summary>
+    public class DataMigrationCoordinator : IFeatureEventHandler {
+        private readonly IDataMigrationManager _dataMigrationManager;
+
+        public DataMigrationCoordinator(IDataMigrationManager dataMigrationManager) {
+            _dataMigrationManager = dataMigrationManager;
+        }
+
+        public void Install(Feature feature) {
+            var featureName = feature.Descriptor.Name;
+            if ( !_dataMigrationManager.IsFeatureAlreadyInstalled(featureName) ) {
+                _dataMigrationManager.Update(featureName);
+            }
+        }
+
+        public void Enable(Feature feature) {
+        }
+
+        public void Disable(Feature feature) {
+        }
+
+        public void Uninstall(Feature feature) {
+        }
+    }
+}

src/Orchard/DataMigration/DataMigrationManager.cs

@@ -4,8 +4,10 @@ using System.Linq;
 using System.Reflection;
 using System.Text.RegularExpressions;
 using Orchard.Data;
+using Orchard.DataMigration.Schema;
+using Orchard.Environment.Configuration;
 using Orchard.Environment.Extensions;
-using Orchard.Environment.Extensions.Models;
+using Orchard.Environment.State;
 using Orchard.Logging;
 
 namespace Orchard.DataMigration {
@@ -17,34 +19,46 @@ namespace Orchard.DataMigration {
         private readonly IRepository<DataMigrationRecord> _dataMigrationRepository;
         private readonly IDataMigrationGenerator _dataMigrationGenerator;
         private readonly IExtensionManager _extensionManager;
+        private readonly ShellSettings _shellSettings;
 
         public DataMigrationManager(
             IEnumerable<IDataMigration> dataMigrations, 
             IRepository<DataMigrationRecord> dataMigrationRepository,
             IDataMigrationGenerator dataMigrationGenerator,
-            IExtensionManager extensionManager) {
+            IExtensionManager extensionManager,
+            ShellSettings shellSettings) {
             _dataMigrations = dataMigrations;
             _dataMigrationRepository = dataMigrationRepository;
             _dataMigrationGenerator = dataMigrationGenerator;
             _extensionManager = extensionManager;
+            _shellSettings = shellSettings;
             Logger = NullLogger.Instance;
         }
 
         public ILogger Logger { get; set; }
 
-        public void Upgrade(string feature) {
+        public IEnumerable<string> GetFeaturesThatNeedUpdate() {
+            throw new NotImplementedException();
+        }
+
+        public void Update(IEnumerable<string> features) {
+            foreach(var feature in features) {
+                Update(feature);
+            }
+        }
+
+        public void Update(string feature){
             
             // proceed with dependent features first, whatever the module it's in
-            var dependencies = _extensionManager
-                .AvailableExtensions()
-                .SelectMany(e => e.Features)
+            var dependencies = ShellStateCoordinator.OrderByDependencies(_extensionManager.AvailableExtensions()
+                .SelectMany(ext => ext.Features))
                 .Where(f => String.Equals(f.Name, feature, StringComparison.OrdinalIgnoreCase))
                 .Where(f => f.Dependencies != null)
                 .SelectMany( f => f.Dependencies )
                 .ToList();
 
             foreach(var dependency in dependencies) {
-                Upgrade(dependency);
+                Update(dependency);
             }
 
             var migrations = GetDataMigrations(feature);
@@ -55,9 +69,7 @@ namespace Orchard.DataMigration {
                 var tempMigration = migration;
                 
                 // get current version for this migration
-                var dataMigrationRecord = _dataMigrationRepository.Table
-                    .Where(dm => dm.DataMigrationClass == tempMigration.GetType().FullName)
-                    .FirstOrDefault();
+                var dataMigrationRecord = GetDataMigrationRecord(tempMigration);
 
                 var updateMethodNameRegex = new Regex(@"^UpdateFrom(?<version>\d+)$", RegexOptions.Compiled);
                 var current = 0;
@@ -81,6 +93,7 @@ namespace Orchard.DataMigration {
 
                 // update methods might also be called after Create()
                 var lookupTable = new Dictionary<int, MethodInfo>();
+
                 // construct a lookup table with all managed initial versions
                 foreach(var methodInfo in migration.GetType().GetMethods(BindingFlags.Public | BindingFlags.Instance)) {
                     var match = updateMethodNameRegex.Match(methodInfo.Name);
@@ -96,29 +109,50 @@ namespace Orchard.DataMigration {
                     }
                     catch (Exception ex) {
                         Logger.Error(ex, "An unexpected error orccured while applying migration on {0} from version {1}", feature, current);
+                        throw;
                     }
                 }
 
                 // if current is 0, it means no upgrade/create method was found or succeeded 
-                if ( current != 0 ) {
-                    if (dataMigrationRecord == null) {
-                        _dataMigrationRepository.Create(new DataMigrationRecord {Current = current, DataMigrationClass = migration.GetType().FullName});
-                    }
-                    else {
-                        dataMigrationRecord.Current = current;
-                        _dataMigrationRepository.Update(dataMigrationRecord);
-                    }
+                if (current == 0) {
+                    continue;
+                }
+                if (dataMigrationRecord == null) {
+                    _dataMigrationRepository.Create(new DataMigrationRecord {Current = current, DataMigrationClass = migration.GetType().FullName});
+                }
+                else {
+                    dataMigrationRecord.Current = current;
+                    _dataMigrationRepository.Update(dataMigrationRecord);
                 }
             }
         }
 
+        private DataMigrationRecord GetDataMigrationRecord(IDataMigration tempMigration) {
+            return _dataMigrationRepository.Table
+                .Where(dm => dm.DataMigrationClass == tempMigration.GetType().FullName)
+                .FirstOrDefault();
+        }
+
         /// <summary>
-        /// Returns all the available IDataMigration instances for a specific module
+        /// Returns all the available IDataMigration instances for a specific module, and inject necessary builders
         /// </summary>
-        public IEnumerable<IDataMigration> GetDataMigrations(string feature) {
-            return _dataMigrations
+        private IEnumerable<IDataMigration> GetDataMigrations(string feature) {
+            var migrations = _dataMigrations
                     .Where(dm => String.Equals(dm.Feature, feature, StringComparison.OrdinalIgnoreCase))
                     .ToList();
+
+            foreach (var migration in migrations.OfType<DataMigrationImpl>()) {
+                migration.SchemaBuilder = new SchemaBuilder(_shellSettings.DataTablePrefix);
+            }
+
+            return migrations;
+        }
+
+        /// <summary>
+        /// Whether a feature has already been installed, i.e. one of its Data Migration class has already been processed
+        /// </summary>
+        public bool IsFeatureAlreadyInstalled(string feature) {
+            return GetDataMigrations(feature).Any(dataMigration => GetDataMigrationRecord(dataMigration) != null);
         }
     }
 }

src/Orchard/DataMigration/IDataMigrationManager.cs

@@ -1,5 +1,25 @@
+using System.Collections.Generic;
+
 namespace Orchard.DataMigration {
     public interface IDataMigrationManager : IDependency {
-        void Upgrade(string feature);
+        /// <summary>
+        /// Whether a feature has already been installed, i.e. one of its Data Migration class has already been processed
+        /// </summary>
+        bool IsFeatureAlreadyInstalled(string feature);
+
+        /// <summary>
+        /// Returns the features which have at least one Data Migration class with a corresponding Upgrade method to be called
+        /// </summary>
+        IEnumerable<string> GetFeaturesThatNeedUpdate();
+
+        /// <summary>
+        /// Updates the database to the latest version for the specified feature
+        /// </summary>
+        void Update(string feature);
+
+        /// <summary>
+        /// Updates the database to the latest version for the specified features
+        /// </summary>
+        void Update(IEnumerable<string> features);
     }
 }

src/Orchard/DataMigration/Schema/AlterColumnCommand.cs

@@ -0,0 +1,15 @@
+namespace Orchard.DataMigration.Schema {
+    public class AlterColumnCommand : ColumnCommand {
+        private string _newName;
+
+        public AlterColumnCommand(string name)
+            : base(name) {
+        }
+
+
+        public AlterColumnCommand Rename(string name) {
+            _newName = name;
+            return this;
+        }
+    }
+}

src/Orchard/DataMigration/Schema/AlterTableCommand.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Data;
+
+namespace Orchard.DataMigration.Schema {
+    public class AlterTableCommand : SchemaCommand {
+        public AlterTableCommand(string name)
+            : base(name) {
+        }
+
+        public AlterTableCommand AddColumn(string name, DbType dbType, Action<CreateColumnCommand> column = null) {
+            var command = new CreateColumnCommand(name);
+            command.Type(dbType);
+            
+            if(column != null) {
+                column(command);
+            }
+            
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public AlterTableCommand DropColumn(string name) {
+            var command = new DropColumnCommand(name);
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public AlterTableCommand AlterColumn(string name, Action<AlterColumnCommand> column = null) {
+            var command = new AlterColumnCommand(name);
+
+            if ( column != null ) {
+                column(command);
+            }
+
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public AlterTableCommand CreateIndex(string name, params string[] columnNames) {
+            var command = new CreateIndexCommand(name, columnNames);
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public AlterTableCommand DropIndex(string name) {
+            var command = new DropIndexCommand(name);
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public AlterTableCommand AddForeignKey(string name, Action<CreateForeignKeyCommand> fk) {
+            var command = new CreateForeignKeyCommand(name);
+            fk(command);
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public AlterTableCommand DropForeignKey(string name) {
+            var command = new DropForeignKeyCommand(name);
+            _tableCommands.Add(command);
+            return this;
+        }
+    }
+}

src/Orchard/DataMigration/Schema/ColumnCommand.cs

@@ -0,0 +1,23 @@
+using System.Data;
+
+namespace Orchard.DataMigration.Schema {
+    public class ColumnCommand : TableCommand {
+        private DbType _dbType;
+        private object _default;
+        public ColumnCommand(string name) : base(name) {
+            _dbType = DbType.Object;
+            _default = null;
+        }
+
+        public ColumnCommand Type(DbType dbType) {
+            _dbType = dbType;
+            return this;
+        }
+
+        public ColumnCommand Default(object @default) {
+            _default = @default;
+            return this;
+        }
+
+   }
+}

src/Orchard/DataMigration/Schema/CreateColumnCommand.cs

@@ -0,0 +1,60 @@
+namespace Orchard.DataMigration.Schema {
+    public class CreateColumnCommand : ColumnCommand {
+        private bool _primaryKey;
+        private byte? _precision;
+        private byte? _scale;
+        private int? _length;
+        private bool _notNull;
+        private bool _unique;
+        
+
+        public CreateColumnCommand(string name) : base(name) {
+            _precision = null;
+            _scale = null;
+            _length = null;
+            _notNull = false;
+            _unique = false;
+            
+        }
+
+        public CreateColumnCommand PrimaryKey() {
+            _primaryKey = true;
+            return this;
+        }
+
+        public CreateColumnCommand Precision(byte? precision) {
+            _precision = precision;
+            return this;
+        }
+
+        public CreateColumnCommand Scale(byte? scale) {
+            _scale = scale;
+            return this;
+        }
+
+        public CreateColumnCommand Length(int? length) {
+            _length = length;
+            return this;
+        }
+
+        public CreateColumnCommand NotNull() {
+            _notNull = true;
+            return this;
+        }
+
+        public CreateColumnCommand Nullable() {
+            _notNull = false;
+            return this;
+        }
+
+        public CreateColumnCommand Unique() {
+            _unique = true;
+            return this;
+        }
+
+        public CreateColumnCommand NotUnique() {
+            _unique = false;
+            return this;
+        }
+    }
+}

src/Orchard/DataMigration/Schema/CreateForeignKeyCommand.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+
+namespace Orchard.DataMigration.Schema {
+    public class CreateForeignKeyCommand : TableCommand {
+        protected readonly List<ForeignKeyClause> _foreignKeyClauses;
+
+        public CreateForeignKeyCommand(string name)
+            : base(name) {
+                _foreignKeyClauses = new List<ForeignKeyClause>();
+        }
+
+        public CreateForeignKeyCommand On(string srcColumn, string destTable, string destColumn) {
+            _foreignKeyClauses.Add(new ForeignKeyClause(srcColumn, destTable, destColumn));
+            return this;
+        }
+    }
+
+    public class ForeignKeyClause {
+        public ForeignKeyClause(string srcColumn, string destTable, string destColumn) {
+            SrcColumn = srcColumn;
+            DestTable = destTable;
+            DestColumn = destColumn;
+        }
+
+        public string DestColumn { get; private set; }
+
+        public string DestTable { get; private set; }
+
+        public string SrcColumn { get; private set; }
+    }
+}

src/Orchard/DataMigration/Schema/CreateIndexCommand.cs

@@ -0,0 +1,10 @@
+namespace Orchard.DataMigration.Schema {
+    public class CreateIndexCommand : TableCommand {
+        public CreateIndexCommand(string name, params string[] columnNames)
+            : base(name) {
+            ColumnNames = columnNames;
+        }
+
+        public string[] ColumnNames { get; private set; }
+    }
+}

src/Orchard/DataMigration/Schema/CreateTableCommand.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Data;
+
+namespace Orchard.DataMigration.Schema {
+    public class CreateTableCommand : SchemaCommand {
+        public CreateTableCommand(string name)
+            : base(name) {
+        }
+
+        public CreateTableCommand Column(string name, DbType dbType, Action<CreateColumnCommand> column = null) {
+            var command = new CreateColumnCommand(name);
+            command.Type(dbType);
+
+            if ( column != null ) {
+                column(command);
+            }
+            _tableCommands.Add(command);
+            return this;
+        }
+
+        public CreateTableCommand ContentPartRecord() {
+            /// TODO: Call Column() with necessary information for content part records
+            return this;
+        }
+
+        public CreateTableCommand VersionedContentPartRecord() {
+            /// TODO: Call Column() with necessary information for content part records
+            return this;
+        }
+
+        public CreateTableCommand ForeignKey(string name, Action<CreateForeignKeyCommand> fk) {
+            var command = new CreateForeignKeyCommand(name);
+            fk(command);
+            _tableCommands.Add(command);
+            return this;
+        }
+    }
+}

src/Orchard/DataMigration/Schema/DropColumnCommand.cs

@@ -0,0 +1,8 @@
+namespace Orchard.DataMigration.Schema {
+    public class DropColumnCommand : ColumnCommand {
+        public DropColumnCommand(string name)
+            : base(name) {
+            
+        }
+    }
+}

src/Orchard/DataMigration/Schema/DropForeignKeyCommand.cs

@@ -0,0 +1,8 @@
+namespace Orchard.DataMigration.Schema {
+    public class DropForeignKeyCommand : TableCommand {
+
+        public DropForeignKeyCommand(string name)
+            : base(name) {
+        }
+    }
+}

src/Orchard/DataMigration/Schema/DropIndexCommand.cs

@@ -0,0 +1,8 @@
+namespace Orchard.DataMigration.Schema {
+    public class DropIndexCommand : TableCommand {
+
+        public DropIndexCommand(string name)
+            : base(name) {
+        }
+    }
+}

src/Orchard/DataMigration/Schema/DropTableCommand.cs

@@ -0,0 +1,7 @@
+namespace Orchard.DataMigration.Schema {
+    public class DropTableCommand : SchemaCommand {
+        public DropTableCommand(string name)
+            : base(name) {
+        }
+    }
+}

src/Orchard/DataMigration/Schema/SchemaBuilder.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+
+namespace Orchard.DataMigration.Schema {
+    public class SchemaBuilder {
+
+        private readonly List<SchemaCommand> _schemaCommands;
+
+        public SchemaBuilder() {
+            _schemaCommands = new List<SchemaCommand>();
+        }
+
+        public SchemaBuilder(string tablePrefix) : this() {
+            TablePrefix = tablePrefix;
+        }
+
+        public string TablePrefix { get; private set; }
+
+        public SchemaBuilder CreateTable(string name, Action<CreateTableCommand> table) {
+            var createTable = new CreateTableCommand(name);
+            table(createTable);
+            _schemaCommands.Add(createTable);
+            return this;
+        }
+
+        public SchemaBuilder AlterTable(string name, Action<AlterTableCommand> table) {
+            var alterTable = new AlterTableCommand(name);
+            table(alterTable);
+            _schemaCommands.Add(alterTable);
+            return this;
+        }
+
+        public SchemaBuilder DropTable(string name) {
+            var deleteTable = new DropTableCommand(name);
+            _schemaCommands.Add(deleteTable);
+            return this;
+        }
+
+        public SchemaBuilder ExecuteSql(string sql, Action<SqlStatementCommand> statement) {
+            var sqlStatmentCommand = new SqlStatementCommand(sql);
+            statement(sqlStatmentCommand);
+            return this;
+        }
+
+    }
+}

src/Orchard/DataMigration/Schema/SchemaCommand.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+
+namespace Orchard.DataMigration.Schema {
+    public class SchemaCommand {
+        protected readonly List<TableCommand> _tableCommands;
+
+        public SchemaCommand(string tableName) {
+            _tableCommands = new List<TableCommand>();
+            Name(tableName);
+        }
+
+        public string TableName { get; private set; }
+
+        public SchemaCommand Name(string name) {
+            TableName = name;
+            return this;
+        }
+    }
+}

src/Orchard/DataMigration/Schema/SqlStatementCommand.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+
+namespace Orchard.DataMigration.Schema {
+    public class SqlStatementCommand : SchemaCommand {
+        protected readonly List<string> _dialects;
+        public SqlStatementCommand(string sql)
+            : base("") {
+            Sql = sql;
+            _dialects = new List<string>();
+        }
+
+        public string Sql { get; private set; }
+
+        public SqlStatementCommand ForDialect(string dialect) {
+            _dialects.Add(dialect);
+            return this;
+        }
+    }
+}

src/Orchard/DataMigration/Schema/TableCommand.cs

@@ -0,0 +1,10 @@
+namespace Orchard.DataMigration.Schema {
+    public class TableCommand {
+        private string _name;
+
+        public TableCommand(string name) {
+            _name = name;
+        }
+
+    }
+}

src/Orchard/Environment/State/ShellStateCoordinator.cs

@@ -195,7 +195,7 @@ namespace Orchard.Environment.State {
             }
         }
 
-        private static IEnumerable<FeatureDescriptor> OrderByDependencies(IEnumerable<FeatureDescriptor> descriptors) {
+        public static IEnumerable<FeatureDescriptor> OrderByDependencies(IEnumerable<FeatureDescriptor> descriptors) {
             var population = descriptors.Select(d => new Linkage {
                 Feature = d
             }).ToArray();

src/Orchard/Orchard.Framework.csproj

@@ -349,7 +349,19 @@
     <Compile Include="ContentManagement\ViewModels\TemplateViewModel.cs">
       <SubType>Code</SubType>
     </Compile>
+    <Compile Include="DataMigration\Schema\SqlStatementCommand.cs" />
+    <Compile Include="DataMigration\Schema\CreateColumnCommand.cs" />
+    <Compile Include="DataMigration\Schema\CreateForeignKeyCommand.cs" />
+    <Compile Include="DataMigration\Schema\DropForeignKeyCommand.cs" />
+    <Compile Include="DataMigration\Schema\DropIndexCommand.cs" />
+    <Compile Include="DataMigration\Schema\CreateIndexCommand.cs" />
+    <Compile Include="DataMigration\Schema\DropColumnCommand.cs" />
+    <Compile Include="DataMigration\Schema\AlterColumnCommand.cs" />
+    <Compile Include="DataMigration\Schema\DropTableCommand.cs" />
+    <Compile Include="DataMigration\Schema\AlterTableCommand.cs" />
     <Compile Include="DataMigration\Commands\DataMigrationCommands.cs" />
+    <Compile Include="DataMigration\Schema\SchemaBuilder.cs" />
+    <Compile Include="DataMigration\DataMigrationCoordinator.cs" />
     <Compile Include="DataMigration\IDataMigrationCommand.cs" />
     <Compile Include="DataMigration\DefaultDataMigrationGenerator.cs" />
     <Compile Include="DataMigration\IDataMigrationGenerator.cs" />
@@ -358,6 +370,10 @@
     <Compile Include="DataMigration\DataMigrationRecord.cs" />
     <Compile Include="DataMigration\IDataMigration.cs" />
     <Compile Include="DataMigration\IDataMigrationManager.cs" />
+    <Compile Include="DataMigration\Schema\ColumnCommand.cs" />
+    <Compile Include="DataMigration\Schema\CreateTableCommand.cs" />
+    <Compile Include="DataMigration\Schema\TableCommand.cs" />
+    <Compile Include="DataMigration\Schema\SchemaCommand.cs" />
     <Compile Include="Data\SessionLocator.cs" />
     <Compile Include="Data\IRepository.cs" />
     <Compile Include="Data\ISessionLocator.cs" />