sql.sql

select internalas0_.Id                                as Id30_,
       internalas0_.InternalAssessmentConfigurationId as Internal2_30_,
       internalas0_.InternalAssessorId                as Internal3_30_,
       internalas0_.ZipCode                           as ZipCode30_
from   dbo.InternalAssessmentMap internalas0_
where  replace(cast(internalas0_.ZipCode as nvarchar(50)), ' ' /* @p0 */, '' /* @p1 */) = '6123' /* @p2 */

test.cs

  	[Test]
		public void should_be_able_to_use_replace_for_strings_in_sql()
		{
			using (new SessionScope())
			{
				Query<InternalAssessmentMap>().Where(x => x.ZipCode.ToString().Replace(" ", "") == "6123").ToList();
			}
		}