diff --git a/advlabdb/database_import.py b/advlabdb/database_import.py
index f0f9e2f..af833a6 100644
--- a/advlabdb/database_import.py
+++ b/advlabdb/database_import.py
@@ -4,6 +4,7 @@ from pathlib import Path
 from shutil import copy2
 
 from flask import flash, has_request_context
+from sqlalchemy import select
 
 from . import db
 from .exceptions import DataBaseImportException
@@ -144,9 +145,15 @@ def importFromFile(filePath):
 
         semesterLabel = not_nullable(semesters["label"][0])
         semesterYear = int(not_nullable(semesters["year"][0]))
-        dbSemester = Semester.query.filter(Semester.label == semesterLabel, Semester.year == semesterYear).first()
+        dbSemester = (
+            db.session.execute(
+                select(Semester).where(Semester.label == semesterLabel, Semester.year == semesterYear).limit(1)
+            )
+            .scalars()
+            .first()
+        )
 
-        if not dbSemester:
+        if dbSemester is None:
             raise DataBaseImportException(
                 f"{semesterLabel}{semesterYear} does not exist in the database! Please make sure that you create the semester from the web interface first."
             )
@@ -159,13 +166,22 @@ def importFromFile(filePath):
             id = int(not_nullable(id))
             partNumber = int(not_nullable(parts["number"][i]))
             partProgramLabel = not_nullable(parts["program_label"][i])
-            dbPart = Part.query.filter(
-                Part.number == partNumber,
-                Part.program.has(Program.label == partProgramLabel),
-                Part.semester == dbSemester,
-            ).first()
+            dbPart = (
+                db.session.execute(
+                    select(Part)
+                    .join(Program)
+                    .where(
+                        Part.number == partNumber,
+                        Program.label == partProgramLabel,
+                        Part.semester == dbSemester,
+                    )
+                    .limit(1)
+                )
+                .scalars()
+                .first()
+            )
 
-            if not dbPart:
+            if dbPart is None:
                 raise DataBaseImportException(
                     f"Part with number {partNumber} and program label {partProgramLabel} does not exist in the database! Please make sure that you create parts from the web interface first."
                 )
@@ -178,9 +194,13 @@ def importFromFile(filePath):
         dbStudents = {}
         for i, studentNumber in enumerate(students["student_number"]):
             studentNumber = int(not_nullable(studentNumber))
-            dbStudent = Student.query.filter(Student.student_number == studentNumber).first()
+            dbStudent = (
+                db.session.execute(select(Student).where(Student.student_number == studentNumber).limit(1))
+                .scalars()
+                .first()
+            )
 
-            if not dbStudent:
+            if dbStudent is None:
                 dbStudent = Student(
                     student_number=studentNumber,
                     first_name=not_nullable(students["first_name"][i]),
@@ -206,9 +226,16 @@ def importFromFile(filePath):
         dbGroups = {}
         for i, id in enumerate(groups["id"]):
             id = int(not_nullable(id))
+            program = (
+                db.session.execute(
+                    select(Program).where(Program.label == not_nullable(groups["program_label"][i])).limit(1)
+                )
+                .scalars()
+                .first()
+            )
             dbGroup = Group(
                 number=int(not_nullable(groups["number"][i])),
-                program=Program.query.filter(Program.label == not_nullable(groups["program_label"][i])).first(),
+                program=program,
                 semester=dbSemester,
             )
             db.session.add(dbGroup)
@@ -233,24 +260,41 @@ def importFromFile(filePath):
         for i, id in enumerate(experiments["id"]):
             id = int(not_nullable(id))
             experimentNumber = int(not_nullable(experiments["number"][i]))
-            experimentProgram = Program.query.filter(
-                Program.label == not_nullable(experiments["program_label"][i])
-            ).first()
-            dbExperiment = Experiment.query.filter(
-                Experiment.number == experimentNumber, Experiment.program == experimentProgram
-            ).first()
 
-            if not dbExperiment:
+            experimentProgram = (
+                db.session.execute(
+                    select(Program).where(Program.label == not_nullable(experiments["program_label"][i])).limit(1)
+                )
+                .scalars()
+                .first()
+            )
+            dbExperiment = (
+                db.session.execute(
+                    select(Experiment)
+                    .where(Experiment.number == experimentNumber, Experiment.program == experimentProgram)
+                    .limit(1)
+                )
+                .scalars()
+                .first()
+            )
+
+            if dbExperiment is None:
                 # TODO: Check if experimentProgram is None
                 raise DataBaseImportException(
                     f"Experiment with number {experimentNumber} and program {experimentProgram.repr()} does not exist in the database. Please make sure that experiments are created from the web interface."
                 )
 
-            dbSemesterExperiment = SemesterExperiment.query.filter(
-                SemesterExperiment.experiment == dbExperiment, SemesterExperiment.semester == dbSemester
-            ).first()
+            dbSemesterExperiment = (
+                db.session.execute(
+                    select(SemesterExperiment)
+                    .where(SemesterExperiment.experiment == dbExperiment, SemesterExperiment.semester == dbSemester)
+                    .limit(1)
+                )
+                .scalars()
+                .first()
+            )
 
-            if not dbSemesterExperiment:
+            if dbSemesterExperiment is None:
                 raise DataBaseImportException(
                     f"No semester experiment exists in the database to the experiment with number {experimentNumber} and program {experimentProgram.repr()}. Please make sure that semester experiments are created in the web interface. The problem might be that the experiment was not active while creating a new semester"
                 )
@@ -276,7 +320,11 @@ def importFromFile(filePath):
         for i, date in enumerate(appointments["date"]):
             date = not_nullable(date)
             assistantEmail = not_nullable(appointments["assistant_email"][i])
-            assistant = Assistant.query.filter(Assistant.user.has(User.email == assistantEmail)).first()
+            assistant = (
+                db.session.execute(select(Assistant).join(User).where(User.email == assistantEmail).limit(1))
+                .scalars()
+                .first()
+            )
 
             if assistant is None:
                 raise DataBaseImportException(