EntityFrameworkCore中linq转sql

public class IQueryableExtensions  

{

   private static readonly TypeInfo QueryCompilerTypeInfo = typeof(QueryCompiler).GetTypeInfo();

   private static readonly FieldInfo QueryCompilerField = typeof(EntityQueryProvider).GetTypeInfo().DeclaredFields.First(x => x.Name == "_queryCompiler");

   private static readonly PropertyInfo NodeTypeProviderField = QueryCompilerTypeInfo.DeclaredProperties.Single(x => x.Name == "NodeTypeProvider");

   private static readonly MethodInfo CreateQueryParserMethod = QueryCompilerTypeInfo.DeclaredMethods.First(x => x.Name == "CreateQueryParser");

   private static readonly FieldInfo DataBaseField = QueryCompilerTypeInfo.DeclaredFields.Single(x => x.Name == "_database");

   private static readonly FieldInfo QueryCompilationContextFactoryField = typeof(Database).GetTypeInfo().DeclaredFields.Single(x => x.Name == "_queryCompilationContextFactory");

   public static string ToSqlTEntity>(this IQueryableTEntity> query) where TEntity : class

   {

       if (!(query is EntityQueryableTEntity>) && !(query is InternalDbSetTEntity>))

       {

           throw new ArgumentException("Invalid query");