Return default value for JetDateTimeTypeMapping derived classes as well. (#102)

src/EFCore.Jet/Migrations/JetMigrationsSqlGenerator.cs

@@ -771,18 +771,16 @@ namespace Microsoft.EntityFrameworkCore.Migrations
             }
             else if (defaultValue != null)
             {
-                var typeMapping = columnType != null
-                    ? Dependencies.TypeMappingSource.FindMapping(defaultValue.GetType(), columnType)
-                    : null;
-                if (typeMapping == null)
-                {
-                    typeMapping = Dependencies.TypeMappingSource.GetMappingForValue(defaultValue);
-                }
-
-                defaultValue = defaultValue.GetType().IsTimeRelatedType()
-                    ? JetDateTimeTypeMapping.GenerateNonNullSqlLiteral(defaultValue, true, _options.EnableMillisecondsSupport)
+                var typeMapping = (columnType != null
+                                      ? Dependencies.TypeMappingSource.FindMapping(defaultValue.GetType(), columnType)
+                                      : null) ??
+                                  Dependencies.TypeMappingSource.GetMappingForValue(defaultValue);
+
+                // All time related type mappings derive from JetDateTimeTypeMapping.
+                defaultValue = typeMapping is JetDateTimeTypeMapping dateTimeTypeMapping
+                    ? dateTimeTypeMapping.GenerateNonNullSqlLiteral(defaultValue, defaultClauseCompatible: true)
                     : typeMapping.GenerateSqlLiteral(defaultValue);
-                
+
                 builder
                     .Append(" DEFAULT ")
                     .Append(defaultValue);

src/EFCore.Jet/Storage/Internal/JetDateTimeOffsetTypeMapping.cs

@@ -45,10 +45,7 @@ namespace EntityFrameworkCore.Jet.Storage.Internal
             base.ConfigureParameter(parameter);
         }
 
-        protected override string GenerateNonNullSqlLiteral(object value)
-            => base.GenerateNonNullSqlLiteral(
-                value is DateTimeOffset dateTimeOffset
-                    ? dateTimeOffset.UtcDateTime
-                    : value);
+        protected override DateTime ConvertToDateTimeCompatibleValue(object value)
+            => ((DateTimeOffset) value).UtcDateTime;
     }
 }

src/EFCore.Jet/Storage/Internal/JetDateTimeTypeMapping.cs

@@ -53,17 +53,17 @@ namespace EntityFrameworkCore.Jet.Storage.Internal
         }
 
         protected override string GenerateNonNullSqlLiteral(object value)
-            => GenerateNonNullSqlLiteral(value, false, _options.EnableMillisecondsSupport);
+            => GenerateNonNullSqlLiteral(value, false);
 
-        public static string GenerateNonNullSqlLiteral(object value, bool defaultClauseCompatible, bool millisecondsSupportEnabled)
+        public virtual string GenerateNonNullSqlLiteral(object value, bool defaultClauseCompatible)
         {
-            var dateTime = (DateTime) value;
+            var dateTime = ConvertToDateTimeCompatibleValue(value);
 
             dateTime = CheckDateTimeValue(dateTime);
 
             if (defaultClauseCompatible)
             {
-                return _decimalTypeMapping.GenerateSqlLiteral(GetDateTimeDoubleValueAsDecimal(dateTime, millisecondsSupportEnabled));
+                return _decimalTypeMapping.GenerateSqlLiteral(GetDateTimeDoubleValueAsDecimal(dateTime, _options.EnableMillisecondsSupport));
             }
             
             var literal = new StringBuilder()
@@ -77,7 +77,7 @@ namespace EntityFrameworkCore.Jet.Storage.Internal
 
             literal.Append("#");
                 
-            if (millisecondsSupportEnabled &&
+            if (_options.EnableMillisecondsSupport &&
                 time != TimeSpan.Zero)
             {
                 // Round to milliseconds.
@@ -97,6 +97,9 @@ namespace EntityFrameworkCore.Jet.Storage.Internal
             return literal.ToString();
         }
 
+        protected virtual DateTime ConvertToDateTimeCompatibleValue(object value)
+            => (DateTime) value;
+
         private static decimal GetDateTimeDoubleValueAsDecimal(DateTime dateTime, bool millisecondsSupportEnabled)
         {
             //

src/EFCore.Jet/Storage/Internal/JetTimeSpanTypeMapping.cs

@@ -28,7 +28,7 @@ namespace EntityFrameworkCore.Jet.Storage.Internal
         protected override RelationalTypeMapping Clone(RelationalTypeMappingParameters parameters)
             => new JetTimeSpanTypeMapping(parameters, _options);
         
-        protected override string GenerateNonNullSqlLiteral(object value)
-            => base.GenerateNonNullSqlLiteral(JetConfiguration.TimeSpanOffset + (TimeSpan) value);
+        protected override DateTime ConvertToDateTimeCompatibleValue(object value)
+            => JetConfiguration.TimeSpanOffset + (TimeSpan) value;
     }
 }