EF4 and bulk delete

When you want to delete records in EF4 typically you load the objects and delete them in the database context. This is a little slow. Microsoft recommends in such cases to use a stored procedure which I find not so cool. Here is an alternative way of doing this:

        public void DeleteAll(IQueryable clause) where TEntity : class
        {
            string sqlClause = GetClause(clause);
            this.context.ExecuteStoreCommand(string.Format(CultureInfo.InvariantCulture, "DELETE {0}", sqlClause));
        }


        private string GetClause(IQueryable clause) where TEntity : class
        {
            string snippet = "FROM [dbo].[";

            string sql = ((ObjectQuery)clause).ToTraceString();
            string sqlFirstPart = sql.Substring(sql.IndexOf(snippet));

            sqlFirstPart = sqlFirstPart.Replace("AS [Extent1]", "");
            sqlFirstPart = sqlFirstPart.Replace("[Extent1].", "");

            // The above code works well for clauses like
            //     IQueryable clause = this.databaseContext.Query().Where(v => v.ModelRunId == 1);
            // BUT as soon as you replace "v => v.ModelRunId == 1" with "v => v.ModelRunId == myId" you will get sql looking like:
            // "SELECT \r\n[Extent1].[LOSS_FILE_ID] AS [LOSS_FILE_ID], \r\n ...WHERE [Extent1].[MODEL_RUN_ID] = @p__linq__0"
            // To evaluate @p__linq__0 you need to use the code below:
            foreach (ObjectParameter Param in (((ObjectQuery)clause)).Parameters) {
                switch (Param.ParameterType.FullName)
                {
                    case "System.Int32":
                        sqlFirstPart = sqlFirstPart.Replace("@"+Param.Name, Param.Value.ToString());
                        break;
                    case "System.String":
                        sqlFirstPart = sqlFirstPart.Replace("@"+Param.Name, "'"+Param.Value.ToString().Replace("'","''")+"'");
                        break;

                    default:
                        throw new NotImplementedException("Parameter conversion for this type is not yet implemented");
                }
            }
            return sqlFirstPart;
        }

Now the delete command can be called using a fluent linq clause in the following way:

            IQueryable clause = this.databaseContext.Query().Where(v => v.ModelRunId.Value == ModelRunId);
            this.databaseContext.DeleteAll(clause);