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 > ) && 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 > ) && 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);
04-18 16:48