diff --git a/Einheit_1/2025_5BHITN_Konstantin_Hintermayer_create_schema.sql b/Einheit_1/2025_5BHITN_Konstantin_Hintermayer_create_schema.sql
index 75b0084..0b27e19 100644
--- a/Einheit_1/2025_5BHITN_Konstantin_Hintermayer_create_schema.sql
+++ b/Einheit_1/2025_5BHITN_Konstantin_Hintermayer_create_schema.sql
@@ -1,69 +1,80 @@
-CREATE DATABASE "2025_5bhitn_konstantin_hintermayer_smarter_rentDB";
-GO
-USE "2025_5bhitn_konstantin_hintermayer_smarter_rentDB";
+IF NOT EXISTS (SELECT name FROM sys.databases WHERE name = '2025_5bhitn_konstantin_hintermayer_smarter_rentDB')
+BEGIN
+    CREATE DATABASE [2025_5bhitn_konstantin_hintermayer_smarter_rentDB];
+END;
 GO
 
-DROP TABLE IF EXISTS Rental;
+USE [2025_5bhitn_konstantin_hintermayer_smarter_rentDB];
+GO
 
-DROP TABLE IF EXISTS Customer;
+IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Customer]') AND type = 'U')
+BEGIN
+    CREATE TABLE Customer (
+        id BIGINT NOT NULL IDENTITY (1, 1),
+        [name] VARCHAR(50) NOT NULL,
+        Adress VARCHAR(100) NOT NULL,
+        driverlicenseid VARCHAR(100) NOT NULL,
+        PRIMARY KEY (id)
+    );
+END;
 
-DROP TABLE IF EXISTS [Location];
+IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Location]') AND type = 'U')
+BEGIN
+    CREATE TABLE Location (
+        id BIGINT NOT NULL IDENTITY (1, 1),
+        [name] VARCHAR(250) NOT NULL,
+        [address] VARCHAR(250) NOT NULL,
+        PRIMARY KEY (id)
+    );
+END;
 
-DROP TABLE IF EXISTS Vehicle;
+IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Rental]') AND type = 'U')
+BEGIN
+    CREATE TABLE Rental (
+        id BIGINT NOT NULL IDENTITY (1, 1),
+        rentalStart DATETIME NOT NULL,
+        rentalEnd DATETIME NOT NULL,
+        actualEnd DATETIME NULL,
+        customerID BIGINT NOT NULL,
+        vehicleID BIGINT NOT NULL,
+        PRIMARY KEY (id)
+    );
 
-DROP TABLE IF EXISTS VehicleCategory;
 
-CREATE TABLE Customer (
-    id BIGINT NOT NULL IDENTITY (1, 1),
-    [name] VARCHAR(50) NOT NULL,
-    Adress VARCHAR(100) NOT NULL,
-    driverlicenseid VARCHAR(100) NOT NULL,
-    PRIMARY KEY (id)
-);
+    ALTER TABLE Rental
+    ADD CONSTRAINT FK_Customer_TO_Rental FOREIGN KEY (customerID) REFERENCES Customer (id);
 
-CREATE TABLE Location (
-    id BIGINT NOT NULL IDENTITY (1, 1),
-    [name] VARCHAR(250) NOT NULL,
-    [address] VARCHAR(250) NOT NULL,
-    PRIMARY KEY (id)
-);
+    ALTER TABLE Rental
+    ADD CONSTRAINT FK_Vehicle_TO_Rental FOREIGN KEY (vehicleID) REFERENCES Vehicle (id);
+END;
 
-CREATE TABLE Rental (
-    id BIGINT NOT NULL IDENTITY (1, 1),
-    rentalStart DATETIME NOT NULL,
-    rentalEnd DATETIME NOT NULL,
-    actualEnd DATETIME NULL,
-    customerID BIGINT NOT NULL,
-    vehicleID BIGINT NOT NULL,
-    PRIMARY KEY (id)
-);
+IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Vehicle]') AND type = 'U')
+BEGIN
+    CREATE TABLE Vehicle (
+        id BIGINT NOT NULL IDENTITY (1, 1),
+        brand VARCHAR(50) NOT NULL,
+        model VARCHAR(50) NOT NULL,
+        licensePlate VARCHAR(8) NOT NULL,
+        buyDate DATE NOT NULL,
+        locationID BIGINT NOT NULL,
+        vehicleCategoryID BIGINT NOT NULL,
+        PRIMARY KEY (id)
+    );
 
-CREATE TABLE Vehicle (
-    id BIGINT NOT NULL IDENTITY (1, 1),
-    brand VARCHAR(50) NOT NULL,
-    model VARCHAR(50) NOT NULL,
-    licensePlate VARCHAR(8) NOT NULL,
-    buyDate DATE NOT NULL,
-    locationID BIGINT NOT NULL,
-    vehicleCategoryID BIGINT NOT NULL,
-    PRIMARY KEY (id)
-);
+    ALTER TABLE Vehicle
+    ADD CONSTRAINT FK_Location_TO_Vehicle FOREIGN KEY (locationID) REFERENCES Location (id);
 
-CREATE TABLE VehicleCategory (
-    id BIGINT NOT NULL IDENTITY (1, 1),
-    [description] VARCHAR(250) NOT NULL,
-    pricePerDay DECIMAL NOT NULL,
-    PRIMARY KEY (id)
-);
+    ALTER TABLE Vehicle
+    ADD CONSTRAINT FK_VehicleCategory_TO_Vehicle FOREIGN KEY (vehicleCategoryID) REFERENCES VehicleCategory (id);
+END;
 
-ALTER TABLE Rental
-ADD CONSTRAINT FK_Customer_TO_Rental FOREIGN KEY (customerID) REFERENCES Customer (id);
+IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[VehicleCategory]') AND type = 'U')
+BEGIN
+    CREATE TABLE VehicleCategory (
+        id BIGINT NOT NULL IDENTITY (1, 1),
+        [description] VARCHAR(250) NOT NULL,
+        pricePerDay DECIMAL NOT NULL,
+        PRIMARY KEY (id)
+    );
+END;
 
-ALTER TABLE Rental
-ADD CONSTRAINT FK_Vehicle_TO_Rental FOREIGN KEY (vehicleID) REFERENCES Vehicle (id);
-
-ALTER TABLE Vehicle
-ADD CONSTRAINT FK_Location_TO_Vehicle FOREIGN KEY (locationID) REFERENCES Location (id);
-
-ALTER TABLE Vehicle
-ADD CONSTRAINT FK_VehicleCategory_TO_Vehicle FOREIGN KEY (vehicleCategoryID) REFERENCES VehicleCategory (id);
\ No newline at end of file