Merge branch '6-error-handling-db-connection' into 'main'

- added Error Handling for missing env Variables

Closes #6

See merge request swp-ws21-fahrtenbuch/team-einhorn/fahrtenbuch!6

server/src/db/config.ts

@@ -6,6 +6,12 @@ const dbHost = process.env.DB_HOST
 const dbDriver = process.env.DB_DRIVER as Dialect
 const dbPassword = process.env.DB_PASSWORD
 
+if (!dbName || !dbUser || !dbHost || !dbDriver || !dbPassword){
+    console.error(`Error while reading DB Environment variables! Is maybe the .env file missing?
+DB Name: "${dbName}", Host: "${dbHost}", User: "${dbUser}", DB Driver(e.g. postgres): "${dbDriver}"`)
+    process.exit(9)
+}
+
 const sequelizeConnection = new Sequelize(dbName, dbUser, dbPassword, {
     host: dbHost,
     dialect: dbDriver,