Database configuration in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the default database engine in Django settings.

Django

DATABASES = {
    'default': {
        'ENGINE': '[1]',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}

Drag options to blanks, or click blank then click option'

A'django.db.backends.mysql'

B'django.db.backends.oracle'

C'django.db.backends.postgresql'

D'django.db.backends.sqlite3'

Attempts:

3 left

💡 Hint

Common Mistakes

Using MySQL or PostgreSQL engine strings by default.

Forgetting to include quotes around the engine string.

The default database engine for Django projects is SQLite, specified as 'django.db.backends.sqlite3'.

2fill in blank

medium

Complete the code to specify the database NAME for a PostgreSQL database in Django settings.

Django

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': '[1]',
        'USER': 'myuser',
        'PASSWORD': 'mypassword',
        'HOST': 'localhost',
        'PORT': '5432',
    }
}

Drag options to blanks, or click blank then click option'

Adb.sqlite3

Bmydatabase

Cpostgres

Ddefaultdb

Attempts:

3 left

💡 Hint

Common Mistakes

Using the SQLite file name instead of the PostgreSQL database name.

Leaving the NAME field empty.

The 'NAME' key should be the name of your PostgreSQL database, such as 'mydatabase'.

3fill in blank

hard

Fix the error in the database configuration by completing the missing key for the database user.

Django

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'mydb',
        '[1]': 'admin',
        'PASSWORD': 'secret',
        'HOST': '127.0.0.1',
        'PORT': '3306',
    }
}

Drag options to blanks, or click blank then click option'

A'USERNAME'

B'USER_NAME'

C'USER'

D'LOGIN'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'USERNAME' or 'USER_NAME' instead of 'USER'.

Using 'LOGIN' which is not recognized by Django.

The correct key for the database username in Django settings is 'USER'.

4fill in blank

hard

Fill both blanks to configure a PostgreSQL database with the correct engine and port.

Django

DATABASES = {
    'default': {
        'ENGINE': '[1]',
        'NAME': 'mydb',
        'USER': 'user',
        'PASSWORD': 'pass',
        'HOST': 'localhost',
        'PORT': '[2]',
    }
}

Drag options to blanks, or click blank then click option'

Adjango.db.backends.postgresql

B5432

C3306

Ddjango.db.backends.mysql

Attempts:

3 left

💡 Hint

Common Mistakes

Using MySQL port 3306 with PostgreSQL engine.

Mixing engine and port values.

PostgreSQL uses the engine 'django.db.backends.postgresql' and default port '5432'.

5fill in blank

hard

Fill all three blanks to configure a MySQL database with correct engine, host, and port.

Django

DATABASES = {
    'default': {
        'ENGINE': '[1]',
        'NAME': 'mydb',
        'USER': 'user',
        'PASSWORD': 'pass',
        'HOST': '[2]',
        'PORT': '[3]',
    }
}

Drag options to blanks, or click blank then click option'

Adjango.db.backends.mysql

Blocalhost

C3306

D127.0.0.1

Attempts:

3 left

💡 Hint

Common Mistakes

Using PostgreSQL engine with MySQL port.

Using 'localhost' instead of '127.0.0.1' for host in some cases.

MySQL uses the engine 'django.db.backends.mysql', default host '127.0.0.1', and default port '3306'.

Practice

1. What is the purpose of the ENGINE setting in Django's database configuration?

easy

A. To define the path to the database file

B. To set the username for the database connection

C. To specify the type of database Django should use

D. To configure the database password

Solution

1. Step 1: Understand the role of ENGINE

   The ENGINE setting tells Django which database backend to use, like SQLite, PostgreSQL, or MySQL.

2. Step 2: Differentiate from other settings

   Settings like NAME, USER, and PASSWORD handle connection details, not the database type.

3. Final Answer:

   To specify the type of database Django should use -> Option C

4. Quick Check:

   ENGINE = database type [OK]

Hint: ENGINE always means database type, not credentials [OK]

Common Mistakes:

• Confusing ENGINE with NAME or USER
• Thinking ENGINE sets username or password
• Assuming ENGINE is a file path

2. Which of the following is the correct way to configure a SQLite database in Django's settings.py?

easy

A. """DATABASES = { 'default': { 'ENGINE': 'django.db.backends.mysql', 'NAME': 'mydb' } }"""

B. """DATABASES = { 'default': { 'ENGINE': 'django.db.backends.postgresql', 'NAME': 'mydb' } }"""

C. """DATABASES = { 'default': { 'ENGINE': 'sqlite3', 'NAME': 'db.sqlite3' } }"""

D. """DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': BASE_DIR / 'db.sqlite3' } }"""

Solution

1. Step 1: Identify correct ENGINE for SQLite

   Django uses django.db.backends.sqlite3 as the ENGINE for SQLite databases.

2. Step 2: Check the NAME setting for SQLite

   The NAME should be a path to the SQLite file, commonly BASE_DIR / 'db.sqlite3' using pathlib.

3. Final Answer:

   DATABASES = { 'default': { 'ENGINE': 'django.db.backends.sqlite3', 'NAME': BASE_DIR / 'db.sqlite3' } } -> Option D

4. Quick Check:

   SQLite ENGINE = django.db.backends.sqlite3 [OK]

Hint: SQLite uses django.db.backends.sqlite3 and file path NAME [OK]

Common Mistakes:

• Using 'sqlite3' instead of 'django.db.backends.sqlite3'
• Confusing ENGINE with PostgreSQL or MySQL backends
• Setting NAME as just a string without path

3. Given this Django database configuration snippet, what database will Django connect to?

DATABASES = {
  'default': {
    'ENGINE': 'django.db.backends.postgresql',
    'NAME': 'myproject',
    'USER': 'admin',
    'PASSWORD': 'secret',
    'HOST': 'localhost',
    'PORT': '5432',
  }
}

medium

A. PostgreSQL database named 'myproject' on localhost

B. MySQL database named 'myproject' on localhost

C. SQLite database named 'myproject'

D. No database connection due to missing ENGINE

Solution

1. Step 1: Check the ENGINE setting

   The ENGINE is set to django.db.backends.postgresql, which means Django will use PostgreSQL.

2. Step 2: Identify database details

   The NAME is 'myproject', HOST is 'localhost', and PORT is '5432' which are typical PostgreSQL defaults.

3. Final Answer:

   PostgreSQL database named 'myproject' on localhost -> Option A

4. Quick Check:

   ENGINE = postgresql means PostgreSQL DB [OK]

Hint: ENGINE shows database type; PostgreSQL means option C [OK]

Common Mistakes:

• Assuming SQLite because of 'myproject' name
• Confusing PostgreSQL with MySQL
• Ignoring HOST and PORT settings

4. Identify the error in this Django database configuration:

DATABASES = {
  'default': {
    'ENGINE': 'django.db.backends.mysql',
    'NAME': 'mydb',
    'USER': 'root',
    'PASSWORD': 'pass123',
    'HOST': '',
    'PORT': '',
  }
}

medium

A. NAME must be a file path for MySQL

B. Empty HOST and PORT cause connection failure

C. PASSWORD cannot be empty string

D. ENGINE should be 'django.db.backends.postgresql'

Solution

1. Step 1: Check HOST and PORT values

   HOST and PORT are empty strings, which can cause connection issues because MySQL expects valid host and port or defaults.

2. Step 2: Understand default behavior

   Leaving HOST and PORT empty may work if MySQL uses defaults, but empty strings are not recommended and can cause errors.

3. Final Answer:

   Empty HOST and PORT cause connection failure -> Option B

4. Quick Check:

   HOST and PORT must be valid or omitted [OK]

Hint: Empty strings for HOST/PORT can break MySQL connection [OK]

Common Mistakes:

• Thinking empty strings mean localhost defaults
• Confusing ENGINE with PostgreSQL
• Assuming PASSWORD must be non-empty always

5. You want to configure Django to use PostgreSQL in production but SQLite in development. Which approach correctly handles this in settings.py?

hard

A. Use environment variables to switch ENGINE and NAME based on environment

B. Set ENGINE to PostgreSQL always and change NAME for dev and prod

C. Use SQLite ENGINE and change USER for production

D. Configure both databases in DATABASES and Django picks automatically

Solution

1. Step 1: Understand environment-based configuration

   Using environment variables lets you switch database settings without changing code, ideal for dev vs prod.

2. Step 2: Why other options fail

   Always setting PostgreSQL ENGINE won't work in dev without PostgreSQL installed; changing USER alone doesn't switch DB type; Django does not auto-pick between multiple databases without explicit routing.

3. Final Answer:

   Use environment variables to switch ENGINE and NAME based on environment -> Option A

4. Quick Check:

   Env vars enable flexible DB config [OK]

Hint: Use env vars to switch DB settings per environment [OK]

Common Mistakes:

• Hardcoding production DB in dev settings
• Assuming Django auto-selects DB from multiple configs
• Changing USER does not switch database type