EF Power Tools的Reverse Engineer Code First逆向生成Model时处理计算字段

VS2013上使用EF Power Tools的Reverse Engineer Code First逆向生成Model时，没有处理计算字段。在保存实体时会出现错误。

可以通过修改Mapping.tt解决。

打开Mapping.tt，找到

foreach (var prop in efHost.EntityType.Properties)
    {
        var type = (PrimitiveType)prop.TypeUsage.EdmType;
        var isKey = efHost.EntityType.KeyMembers.Contains(prop);
        var storeProp = efHost.PropertyToColumnMappings[prop];
        var sgpFacet = storeProp.TypeUsage.Facets.SingleOrDefault(f => f.Name == "StoreGeneratedPattern");
        var storeGeneratedPattern = sgpFacet == null
            ? StoreGeneratedPattern.None
            : (StoreGeneratedPattern)sgpFacet.Value;

        var configLines = new List<string>();

        if (type.ClrEquivalentType == typeof(int)
            || type.ClrEquivalentType == typeof(decimal)
            || type.ClrEquivalentType == typeof(short)
            || type.ClrEquivalentType == typeof(long))
        {
            if (isKey && storeGeneratedPattern != StoreGeneratedPattern.Identity)
            {
                configLines.Add(".HasDatabaseGeneratedOption(DatabaseGeneratedOption.None)");
            }
            else if ((!isKey || efHost.EntityType.KeyMembers.Count > 1) && storeGeneratedPattern == StoreGeneratedPattern.Identity)
            {
                configLines.Add(".HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)");
            }
        }

在 var configLines = new List<string>(); 后添加计算字段的内容：

foreach (var prop in efHost.EntityType.Properties)
    {
        var type = (PrimitiveType)prop.TypeUsage.EdmType;
        var isKey = efHost.EntityType.KeyMembers.Contains(prop);
        var storeProp = efHost.PropertyToColumnMappings[prop];
        var sgpFacet = storeProp.TypeUsage.Facets.SingleOrDefault(f => f.Name == "StoreGeneratedPattern");
        var storeGeneratedPattern = sgpFacet == null
            ? StoreGeneratedPattern.None
            : (StoreGeneratedPattern)sgpFacet.Value;

        var configLines = new List<string>();

        if(!isKey && storeGeneratedPattern == StoreGeneratedPattern.Computed)
        {
            configLines.Add(".HasDatabaseGeneratedOption(DatabaseGeneratedOption.Computed)");
        }

        if (type.ClrEquivalentType == typeof(int)
            || type.ClrEquivalentType == typeof(decimal)
            || type.ClrEquivalentType == typeof(short)
            || type.ClrEquivalentType == typeof(long))
        {
            if (isKey && storeGeneratedPattern != StoreGeneratedPattern.Identity)
            {
                configLines.Add(".HasDatabaseGeneratedOption(DatabaseGeneratedOption.None)");
            }
            else if ((!isKey || efHost.EntityType.KeyMembers.Count > 1) && storeGeneratedPattern == StoreGeneratedPattern.Identity)
            {
                configLines.Add(".HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)");
            }
        }

再次使用Reverse Engineer Code First。

得到带计算字段信息的mapping。

            this.Property(t => t.ResetDate)
                .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Computed);

            this.Property(t => t.ResetHour)
                .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Computed);