#19532: Implementing custom AlterColumnCommand query for MySql

Work Item: 19532

--HG--
branch : 1.x

src/Orchard/Data/Migration/Interpreters/DefaultDataMigrationInterpreter.cs

@@ -4,7 +4,6 @@ using System.Data;
 using System.Globalization;
 using System.Linq;
 using System.Text;
-using NHibernate;
 using NHibernate.Dialect;
 using NHibernate.SqlTypes;
 using Orchard.ContentManagement.Records;
@@ -75,7 +74,7 @@ namespace Orchard.Data.Migration.Interpreters {
                 Visit(builder, createColumn);
             }
 
-            var primaryKeys = command.TableCommands.OfType<CreateColumnCommand>().Where(ccc => ccc.IsPrimaryKey).Select(ccc => ccc.ColumnName);
+            var primaryKeys = command.TableCommands.OfType<CreateColumnCommand>().Where(ccc => ccc.IsPrimaryKey).Select(ccc => ccc.ColumnName).ToArray();
             if (primaryKeys.Any()) {
                 if (appendComma) {
                     builder.Append(", ");
@@ -191,7 +190,7 @@ namespace Orchard.Data.Migration.Interpreters {
 
             // type
             if (command.DbType != DbType.Object) {
-                builder.Append(GetTypeName(command.DbType, command.Length, command.Precision, command.Scale));
+                builder.Append(GetTypeName(_dialect, command.DbType, command.Length, command.Precision, command.Scale));
             }
             else {
                 if(command.Length > 0 || command.Precision > 0 || command.Scale > 0) {
@@ -278,23 +277,12 @@ namespace Orchard.Data.Migration.Interpreters {
             RunPendingStatements();
         }
 
-        private string GetTypeName(DbType dbType, int? length, byte precision, byte scale) {
-
-            // NHibernate has a bug in MsSqlCeDialect, as it's declaring the decimal type as this:
-            // NUMERIC(19, $1), where $1 is the Length parameter, and it's wrong. It should be 
-            // NUMERIC(19, $s) in order to use the Scale parameter, as it's done for SQL Server dialects
-            // https://nhibernate.jira.com/browse/NH-2979
-            if (_dialect is NHibernate.Dialect.MsSqlCeDialect
-                && dbType == DbType.Decimal
-                && scale != 0) {
-                return _dialect.GetTypeName(new SqlType(dbType), scale, precision, scale);
-            }
-
+        public static string GetTypeName(Dialect dialect, DbType dbType, int? length, byte precision, byte scale) {
             return precision > 0
-                       ? _dialect.GetTypeName(new SqlType(dbType, precision, scale))
+                       ? dialect.GetTypeName(new SqlType(dbType, precision, scale))
                        : length.HasValue
-                             ? _dialect.GetTypeName(new SqlType(dbType, length.Value))
-                             : _dialect.GetTypeName(new SqlType(dbType));
+                             ? dialect.GetTypeName(new SqlType(dbType, length.Value))
+                             : dialect.GetTypeName(new SqlType(dbType));
         }
 
         private void Visit(StringBuilder builder, CreateColumnCommand command) {
@@ -306,7 +294,7 @@ namespace Orchard.Data.Migration.Interpreters {
             builder.Append(_dialect.QuoteForColumnName(command.ColumnName)).Append(Space);
 
             if (!command.IsIdentity || _dialect.HasDataTypeInIdentityColumn) {
-                builder.Append(GetTypeName(command.DbType, command.Length, command.Precision, command.Scale));
+                builder.Append(GetTypeName(_dialect, command.DbType, command.Length, command.Precision, command.Scale));
             }
 
             // append identity if handled
@@ -368,7 +356,7 @@ namespace Orchard.Data.Migration.Interpreters {
             return false;
         }
 
-        private static string ConvertToSqlValue(object value) {
+        public static string ConvertToSqlValue(object value) {
             if ( value == null ) {
                 return "null";
             }

src/Orchard/Data/Migration/Interpreters/MySqlCommandInterpreter.cs

@@ -0,0 +1,64 @@
+using System.Data;
+using System.Text;
+using NHibernate.Dialect;
+using Orchard.Data.Migration.Schema;
+using Orchard.Environment.Configuration;
+using Orchard.Localization;
+
+namespace Orchard.Data.Migration.Interpreters {
+    public class MySqlCommandInterpreter : ICommandInterpreter<AlterColumnCommand> {
+        private readonly Dialect _dialect;
+        private readonly ShellSettings _shellSettings;
+
+        public MySqlCommandInterpreter() {
+            T = NullLocalizer.Instance;
+        }
+
+        public string DataProvider {
+            get { return "MySql"; }
+        }
+
+        public Localizer T { get; set; }
+
+        public MySqlCommandInterpreter(
+            ShellSettings shellSettings,
+            ISessionFactoryHolder sessionFactoryHolder) {
+                _shellSettings = shellSettings;
+                var configuration = sessionFactoryHolder.GetConfiguration();
+                _dialect = Dialect.GetDialect(configuration.Properties);
+        }
+
+        public string[] CreateStatements(AlterColumnCommand command) {
+            var builder = new StringBuilder();
+            
+            builder.AppendFormat("alter table {0} modify column {1} ",
+                            _dialect.QuoteForTableName(PrefixTableName(command.TableName)),
+                            _dialect.QuoteForColumnName(command.ColumnName));
+
+            // type
+            if (command.DbType != DbType.Object) {
+                builder.Append(DefaultDataMigrationInterpreter.GetTypeName(_dialect, command.DbType, command.Length, command.Precision, command.Scale));
+            }
+            else {
+                if (command.Length > 0 || command.Precision > 0 || command.Scale > 0) {
+                    throw new OrchardException(T("Error while executing data migration: you need to specify the field's type in order to change its properties"));
+                }
+            }
+
+            // [default value]
+            if (command.Default != null) {
+                builder.Append(" set default ").Append(DefaultDataMigrationInterpreter.ConvertToSqlValue(command.Default)).Append(" ");
+            }
+
+            return new [] {
+                builder.ToString()
+            };
+        }
+
+        private string PrefixTableName(string tableName) {
+            if (string.IsNullOrEmpty(_shellSettings.DataTablePrefix))
+                return tableName;
+            return _shellSettings.DataTablePrefix + "_" + tableName;
+        }
+    }
+}

src/Orchard/Orchard.Framework.csproj

@@ -173,6 +173,7 @@
     <Compile Include="Data\AbstractSessionInterceptor.cs" />
     <Compile Include="Data\Bags\SArray.cs" />
     <Compile Include="Data\FetchRequest.cs" />
+    <Compile Include="Data\Migration\Interpreters\MySqlCommandInterpreter.cs" />
     <Compile Include="DisplayManagement\Arguments.cs" />
     <Compile Include="Data\Bags\SConvert.cs" />
     <Compile Include="Data\Bags\Serialization\IBagSerializer.cs" />