Parameter binding mental model in SQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to use a parameter placeholder in the SQL query.

SQL

SELECT * FROM users WHERE username = [1];

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

A$1

B:username

C?

D@username

Attempts:

3 left

💡 Hint

Common Mistakes

Using named placeholders when the library expects positional ones.

Forgetting to use any placeholder and inserting values directly.

The question mark ? is a common placeholder for parameters in SQL queries.

2fill in blank

medium

Complete the code to bind a named parameter in the SQL query.

SQL

SELECT * FROM products WHERE category = [1];

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

A:category

B?

C$1

D@category

Attempts:

3 left

💡 Hint

Common Mistakes

Using positional placeholders instead of named ones.

Omitting the colon before the parameter name.

Named parameters use a colon : followed by the parameter name.

3fill in blank

hard

Fix the error in the SQL query by choosing the correct parameter placeholder.

SQL

UPDATE orders SET status = [1] WHERE order_id = 123;

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

A:status

B$1

C@status

D?

Attempts:

3 left

💡 Hint

Common Mistakes

Using question marks in PostgreSQL queries.

Using named parameters without support in the database.

In PostgreSQL, positional parameters use $1, $2, etc.

4fill in blank

hard

Fill both blanks to correctly bind parameters for a user login query.

SQL

SELECT * FROM users WHERE email = [1] AND password = [2];

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

A?

B:email

C:password

D$1

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing positional and named parameters in the same query.

Using question marks for named parameters.

Named parameters :email and :password are used to bind values safely.

5fill in blank

hard

Fill all three blanks to create a parameterized INSERT statement.

SQL

INSERT INTO employees (name, age, department) VALUES ([1], [2], [3]);

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

A?

B:age

C:department

D:name

Attempts:

3 left

💡 Hint

Common Mistakes

Using question marks for some parameters and named for others.

Not matching parameter names to column names.

Use named parameters :name, :age, and :department to safely insert values.