diff --git a/Backend/endpoints/user-session.go b/Backend/endpoints/user-session.go
index ffed8b9..296fc3b 100644
--- a/Backend/endpoints/user-session.go
+++ b/Backend/endpoints/user-session.go
@@ -18,6 +18,7 @@ var Session *scs.SessionManager
 func CreateSessionManager(lifetime time.Duration) *scs.SessionManager {
 	Session = scs.New()
 	Session.Lifetime = lifetime
+	log.Println("Created Session")
 	return Session
 }
 
@@ -55,14 +56,15 @@ func loginUser(w http.ResponseWriter, r *http.Request) {
 
 	user, err := models.GetUserByPersonalNr(personal_nummer)
 	if err != nil {
-		log.Println("No user found under this personal number!")
+		log.Println("No user found under this personal number!", err)
 		http.Error(w, "No user found!", http.StatusNotFound)
 	}
 
 	password := r.FormValue("password")
 	if user.Login(password) {
-		log.Printf("New succesfull user login from %s %s!\n", user.Vorname, user.Name)
+		log.Printf("New succesfull user login from %s %s (%d)!\n", user.Vorname, user.Name, user.PersonalNummer)
 		Session.Put(r.Context(), "user", user.PersonalNummer)
+		Session.Commit(r.Context())
 		http.Redirect(w, r, "/time", http.StatusSeeOther) //with this browser always uses GET
 	} else {
 		showLoginPage(w, r, true)
diff --git a/Backend/models/db_test.go b/Backend/models/db_test.go
index 629bd2d..be272c5 100644
--- a/Backend/models/db_test.go
+++ b/Backend/models/db_test.go
@@ -36,10 +36,12 @@ func SetupDBFixture(t *testing.T) *DBFixture {
 		t.Fatalf("failed to connect to database: %v", err)
 	}
 
-	// err = MigrateDB(db, "file://../../migrations")
-	// if err != nil && err != migrate.ErrNoChange {
-	// 	t.Fatalf("Failed to migrate database: %v", err)
-	// }
+	defer db.Close()
+
+	err = MigrateDB(db, "file://../../migrations")
+	if err != nil && err != migrate.ErrNoChange {
+		t.Fatalf("Failed to migrate database: %v", err)
+	}
 
 	tx, err := db.Begin()
 	if err != nil {
diff --git a/Backend/models/user_test.go b/Backend/models/user_test.go
index 323f925..c214625 100644
--- a/Backend/models/user_test.go
+++ b/Backend/models/user_test.go
@@ -6,16 +6,20 @@ import (
 	"testing"
 )
 
-var testUser models.User = models.User{Vorname: "Kim", Name: "Mustermensch", PersonalNummer: 456, CardUID: "aaaa-aaaa", ArbeitszeitPerTag: 8}
+var testUser models.User = models.User{Vorname: "Kim", Name: "Mustermensch", PersonalNummer: 456, CardUID: "aaaa-aaaa", ArbeitszeitPerTag: 8, ArbeitszeitPerWoche: 40}
 
 func SetupUserFixture(t *testing.T, db models.IDatabase) {
 	t.Helper()
-	db.Exec(`INSERT INTO "s_personal_daten" ("personal_nummer", "aktiv_beschaeftigt", "vorname", "nachname", "geburtsdatum", "plz", "adresse", "geschlecht", "card_uid", "hauptbeschaeftigungs_ort", "arbeitszeit_per_tag", "arbeitszeit_min_start", "arbeitszeit_max_ende", "vorgesetzter_pers_nr") VALUES
-(456,	't',	'Kim',	'Mustermensch',	'2003-02-01',	'08963',	'Altenburger Str. 44A',	1,	'aaaa-aaaa',	1,	8,	'07:00:00',	'20:00:00',	0);`)
+	_, err := db.Exec(`INSERT INTO s_personal_daten (personal_nummer, aktiv_beschaeftigt, vorname, nachname, geburtsdatum, plz, adresse, geschlecht, card_uid, hauptbeschaeftigungs_ort, arbeitszeit_per_tag, arbeitszeit_per_woche, arbeitszeit_min_start, arbeitszeit_max_ende, vorgesetzter_pers_nr) VALUES
+		(456, 't', 'Kim', 'Mustermensch', '2003-02-01', '08963', 'Altenburger Str. 44A', 1, 'aaaa-aaaa', 1, 8, 40, '07:00:00', '20:00:00', 0);`)
+	if err != nil {
+		t.Fatal("SetupUserFixture:", err)
+	}
 }
 
 func TestGetUserByPersonalNr(t *testing.T) {
 	tc := SetupDBFixture(t)
+
 	SetupUserFixture(t, tc.Database)
 
 	models.DB = tc.Database
@@ -44,12 +48,12 @@ func TestCheckAnwesenheit(t *testing.T) {
 	if actual = testUser.CheckAnwesenheit(); actual != false {
 		t.Errorf("Checkabwesenheit with no booking should be false but is %t", actual)
 	}
-	tc.Database.Exec("INSERT INTO anwesenheit (timestamp, card_uid, check_in_out, geraet_id) VALUES (NOW() - INTERVAL '2 minute', 'aaaa-aaaa', 1, 1);")
+	tc.Database.Exec("INSERT INTO anwesenheit (timestamp, card_uid, check_in_out, geraet_id, anwesenheit_typ) VALUES (NOW() - INTERVAL '2 minute', 'aaaa-aaaa', 1, 1, 1);")
 	if actual = testUser.CheckAnwesenheit(); actual != true {
 		t.Errorf("Checkabwesenheit with 'kommen' booking should be true but is %t", actual)
 	}
 
-	tc.Database.Exec("INSERT INTO anwesenheit (timestamp, card_uid, check_in_out, geraet_id) VALUES (NOW() - INTERVAL '1 minute', 'aaaa-aaaa', 2, 1);")
+	tc.Database.Exec("INSERT INTO anwesenheit (timestamp, card_uid, check_in_out, geraet_id, anwesenheit_typ) VALUES (NOW() - INTERVAL '1 minute', 'aaaa-aaaa', 2, 1, 1);")
 	if actual = testUser.CheckAnwesenheit(); actual != false {
 		t.Errorf("Checkabwesenheit with 'gehen' booking should be false but is %t", actual)
 	}
diff --git a/DB/initdb/01_schema.sql b/DB/initdb/01_schema.sql
index 14b71ad..8547504 100644
--- a/DB/initdb/01_schema.sql
+++ b/DB/initdb/01_schema.sql
@@ -4,11 +4,11 @@
 DROP TABLE IF EXISTS "anwesenheit";
 CREATE TABLE "anwesenheit" (
   "counter_id" bigserial NOT NULL,
-  "timestamp" timestamptz NULL DEFAULT CURRENT_TIMESTAMP,
+  "timestamp" timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
   "card_uid" character varying(255) NOT NULL,
   "check_in_out" smallint NOT NULL,
-  "geraet_id" smallint NULL,
-  "anwesenheit_typ" int2,
+  "geraet_id" smallint NOT NULL,
+  "anwesenheit_typ" int2 NOT NULL,
   PRIMARY KEY ("counter_id")
 );
 
@@ -32,19 +32,19 @@ DROP TABLE IF EXISTS "s_personal_daten";
 CREATE TABLE "s_personal_daten" (
     "personal_nummer" int4 NOT NULL PRIMARY KEY,
     "aktiv_beschaeftigt" bool,
-    "vorname" varchar(255),
-    "nachname" varchar(255),
+    "vorname" varchar(255) NOT NULL,
+    "nachname" varchar(255) NOT NULL,
     "geburtsdatum" date,
     "plz" varchar(255),
     "adresse" varchar(255),
     "geschlecht" int2,
     "card_uid" varchar(255),
     "hauptbeschaeftigungs_ort" int2,
-    "arbeitszeit_per_tag" float4,
-    "arbeitszeit_per_woche" float4,
+    "arbeitszeit_per_tag" float4 NOT NULL,
+    "arbeitszeit_per_woche" float4 NOT NULL,
     "arbeitszeit_min_start" time(6),
     "arbeitszeit_max_ende" time(6),
-    "vorgesetzter_pers_nr" int4
+    "vorgesetzter_pers_nr" int4 NOT NULL
 );
 COMMENT ON COLUMN "s_personal_daten"."geschlecht" IS '1==weiblich, 2==maennlich, 3==divers';
 
@@ -94,7 +94,7 @@ CREATE TABLE "abwesenheit" (
     "datum" timestamptz(6) DEFAULT NOW()::DATE
     );
 
-    DROP TABLE IF EXISTS "s_abwesenheit_typen";
+DROP TABLE IF EXISTS "s_abwesenheit_typen";
 CREATE TABLE "s_abwesenheit_typen" (
     "abwesenheit_id" int2 PRIMARY KEY,
     "abwesenheit_name" varchar(255),
diff --git a/migrations/20250903233030_non_null_contraints.down.sql b/migrations/20250903233030_non_null_contraints.down.sql
new file mode 100644
index 0000000..120b393
--- /dev/null
+++ b/migrations/20250903233030_non_null_contraints.down.sql
@@ -0,0 +1,4 @@
+-- reverse: modify "s_personal_daten" table
+ALTER TABLE "s_personal_daten" ALTER COLUMN "arbeitszeit_per_woche" DROP NOT NULL, ALTER COLUMN "vorgesetzter_pers_nr" DROP NOT NULL, ALTER COLUMN "arbeitszeit_per_tag" DROP NOT NULL, ALTER COLUMN "nachname" DROP NOT NULL, ALTER COLUMN "vorname" DROP NOT NULL;
+-- reverse: modify "anwesenheit" table
+ALTER TABLE "anwesenheit" ALTER COLUMN "anwesenheit_typ" DROP NOT NULL, ALTER COLUMN "geraet_id" DROP NOT NULL, ALTER COLUMN "timestamp" DROP NOT NULL;
diff --git a/migrations/20250903233030_non_null_contraints.up.sql b/migrations/20250903233030_non_null_contraints.up.sql
new file mode 100644
index 0000000..066f92a
--- /dev/null
+++ b/migrations/20250903233030_non_null_contraints.up.sql
@@ -0,0 +1,4 @@
+-- modify "anwesenheit" table
+ALTER TABLE "anwesenheit" ALTER COLUMN "timestamp" SET NOT NULL, ALTER COLUMN "geraet_id" SET NOT NULL, ALTER COLUMN "anwesenheit_typ" SET NOT NULL;
+-- modify "s_personal_daten" table
+ALTER TABLE "s_personal_daten" ALTER COLUMN "vorname" SET NOT NULL, ALTER COLUMN "nachname" SET NOT NULL, ALTER COLUMN "arbeitszeit_per_tag" SET NOT NULL, ALTER COLUMN "vorgesetzter_pers_nr" SET NOT NULL, ALTER COLUMN "arbeitszeit_per_woche" SET NOT NULL;
diff --git a/migrations/atlas.sum b/migrations/atlas.sum
index 18be8b2..f860f4a 100644
--- a/migrations/atlas.sum
+++ b/migrations/atlas.sum
@@ -1,4 +1,4 @@
-h1:hyA7xJMv355hJfvtzD9tKSrkAEtsQ/vVixDZDDBxoh0=
+h1:8l1ysZIcRMDXUdjWvSQVhVJjVUEfiVlYw7Q/jUB0Wn0=
 20250901201159_initial.down.sql h1:cmF5CvNGqEfcmbRgiqaqDWERdNNRaMzarbNLJ/Y35o4=
 20250901201159_initial.up.sql h1:Yrak/+wfQ4Tu/dVR/cUZ/75DlAcv4G/OJXDqpgSw47U=
 20250901201250_control_tables.down.sql h1:f/KmhO9pOI45J8ZRjFonvD3CypB+rOoGOPN2WMFHvOw=
@@ -7,3 +7,5 @@ h1:hyA7xJMv355hJfvtzD9tKSrkAEtsQ/vVixDZDDBxoh0=
 20250901201710_triggers_extension.up.sql h1:nUBPd2eDssi/TwMVF/nOJkIM5rUM0iINdg1K9pZRZN0=
 20250903221313_overtime.down.sql h1:X+jJESqcZ6ZTd2H563z6kRaXb4dn4sA02D3ck2795v8=
 20250903221313_overtime.up.sql h1:C3DSiNVpe9v0Un1DEQ0lsy5yToR8iqcggv91GSr6tRE=
+20250903233030_non_null_contraints.down.sql h1:jAIc4pRyTS/X0qONQKhjhVx891JCA9/KZbx619240AY=
+20250903233030_non_null_contraints.up.sql h1:Ts4CuDO3gP/VSBu1OhnVhiyOIiLnT8qvEf/kHjCmeCU=