我在Erik Jensen的博客文章中找到了答案:
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SqlServerCe.4.0"/>
<add name="Microsoft SQL Server Compact Data Provider 4.0"
invariant="System.Data.SqlServerCe.4.0"
description=".NET Framework Data Provider for Microsoft SQL Server Compact"
type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=4.0.0.1,
Culture=neutral,
PublicKeyToken=89845dcd8080cc91"/>
</DbProviderFactories>
</system.data>