Native SQL queries in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a native SQL query in a Spring Data JPA repository.

Spring Boot

@Query(value = "SELECT * FROM users WHERE id = [1]", nativeQuery = true)
User findUserById(Long id);

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

A:id

B?id

C?1

D:userId

Attempts:

3 left

💡 Hint

Common Mistakes

Using named parameters like :id in native queries causes errors.

The placeholder ?1 refers to the first method parameter in native SQL queries.

2fill in blank

medium

Complete the code to execute a native SQL update query in a Spring Data JPA repository.

Spring Boot

@Modifying
@Query(value = "UPDATE products SET price = [1] WHERE id = ?1", nativeQuery = true)
int updatePriceById(Long id, Double price);

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

A:price

B?price

C?1

D?2

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing parameter order and using ?1 for price.

The placeholder ?2 refers to the second method parameter, which is price here.

3fill in blank

hard

Fix the error in the native query to select users with a specific role.

Spring Boot

@Query(value = "SELECT * FROM users WHERE role = [1]", nativeQuery = true)
List<User> findUsersByRole(String role);

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

A?1

B?role

C:role

D:userRole

Attempts:

3 left

💡 Hint

Common Mistakes

Using named parameters like :role causes errors.

In native queries, positional parameter ?1 correctly refers to the first method argument.

4fill in blank

hard

Fill both blanks to create a native query that deletes products by category and returns affected rows.

Spring Boot

@Modifying
@Query(value = "DELETE FROM products WHERE category = [1] AND available = [2]", nativeQuery = true)
int deleteByCategoryAndAvailability(String category, boolean available);

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

A?1

B:category

C?2

D:available

Attempts:

3 left

💡 Hint

Common Mistakes

Using named parameters causes errors in native queries.

Use positional parameters ?1 and ?2 for the first and second method arguments respectively in native queries.

5fill in blank

hard

Fill all three blanks to write a native query that selects users by status and orders by creation date.

Spring Boot

@Query(value = "SELECT * FROM users WHERE status = [1] ORDER BY [2] [3]", nativeQuery = true)
List<User> findUsersByStatusOrdered(String status, String orderBy, String direction);

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

A?1

Bcreated_at

CASC

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to use parameters for column names or order direction causes errors.

The first blank uses positional parameter ?1 for status. The second and third blanks are column name and order direction respectively.

Practice

1. What annotation is used in Spring Boot to define a native SQL query inside a repository interface?

easy

A. @SqlQuery

B. @NativeQuery

C. @Query with nativeQuery = true

D. @SQLNative

Solution

1. Step 1: Recognize the annotation for queries in Spring Data JPA

   The @Query annotation is used to define custom queries in repository interfaces.

2. Step 2: Identify how to specify native SQL

   Setting nativeQuery = true inside @Query tells Spring Boot to treat the query as native SQL.

3. Final Answer:

   @Query with nativeQuery = true -> Option C

4. Quick Check:

   Native SQL queries use @Query(nativeQuery = true) [OK]

Hint: Look for @Query with nativeQuery true flag [OK]

Common Mistakes:

• Using a non-existent annotation like @NativeQuery
• Forgetting to set nativeQuery = true
• Confusing @Query with @SqlQuery
• Using @SQLNative which is invalid

2. Which of the following is the correct syntax to write a native SQL query in a Spring Boot repository method?

easy

A. @Query(value = "SELECT * FROM users", nativeQuery = true)

B. @Query(native = true, value = "SELECT * FROM users")

C. @NativeQuery("SELECT * FROM users")

D. @Query(sql = "SELECT * FROM users")

Solution

1. Step 1: Recall the correct attribute names in @Query

   The attribute for the query string is value, and to mark it native SQL, use nativeQuery = true.

2. Step 2: Check each option's syntax

   @Query(value = "SELECT * FROM users", nativeQuery = true) correctly uses @Query(value = "...", nativeQuery = true). Options B, C, and D use invalid attribute names or annotations.

3. Final Answer:

   @Query(value = "SELECT * FROM users", nativeQuery = true) -> Option A

4. Quick Check:

   @Query(value=..., nativeQuery=true) is correct syntax [OK]

Hint: Use value= for query and nativeQuery=true [OK]

Common Mistakes:

• Using native=true instead of nativeQuery=true
• Using @NativeQuery annotation which doesn't exist
• Using sql= instead of value= for query string
• Swapping attribute order incorrectly

3. Given this repository method:

@Query(value = "SELECT * FROM products WHERE price > ?1", nativeQuery = true)
List<Product> findExpensiveProducts(double minPrice);

What will be the result of calling findExpensiveProducts(100.0)?

medium

A. List of products with price less than 100.0

B. Empty list always

C. Syntax error due to ?1 placeholder

D. List of products with price greater than 100.0

Solution

1. Step 1: Understand the native SQL query with parameter

   The query selects all products where price is greater than the first parameter (?1), which is passed as 100.0.

2. Step 2: Predict the method output

   Calling findExpensiveProducts(100.0) returns products priced above 100.0, so the list contains those products.

3. Final Answer:

   List of products with price greater than 100.0 -> Option D

4. Quick Check:

   Native query with ?1 uses method parameter [OK]

Hint: ?1 matches first method parameter in native query [OK]

Common Mistakes:

• Thinking ?1 is invalid in native queries
• Confusing greater than with less than
• Assuming empty list without data
• Believing syntax error due to placeholder

4. Identify the error in this native query method:

@Query(value = "SELECT * FROM orders WHERE status = :status", nativeQuery = true)
List<Order> findByStatus(String status);

medium

A. Named parameter :status is not supported in native queries

B. Query string should use ?1 instead of :status

C. Missing nativeQuery = true flag

D. Method return type should be Optional<Order>

Solution

1. Step 1: Check parameter usage in native queries

   Native SQL queries in Spring Boot do not support named parameters like :status by default; they require positional parameters like ?1.

2. Step 2: Identify correct parameter syntax

   The query should use ?1 to refer to the first method parameter instead of :status.

3. Final Answer:

   Query string should use ?1 instead of :status -> Option B

4. Quick Check:

   Native queries use positional parameters like ?1 [OK]

Hint: Use ?1 for parameters in native queries, not :name [OK]

Common Mistakes:

• Using named parameters in native queries
• Forgetting nativeQuery = true
• Assuming return type must be Optional
• Confusing JPQL and native SQL syntax

5. You want to write a native SQL query in Spring Boot to update the price of all products in a category. Which method signature and annotation is correct?

hard

A. @Modifying
@Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1", nativeQuery = true)
int increasePriceByCategory(String category);

B. @Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1", nativeQuery = true)
void increasePriceByCategory(String category);

C. @Modifying
@Query(value = "UPDATE products SET price = price * 1.1 WHERE category = :category", nativeQuery = true)
int increasePriceByCategory(String category);

D. @Modifying
@Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1")
int increasePriceByCategory(String category);

Solution

1. Step 1: Recognize update queries need @Modifying

   In Spring Boot, native update queries require the @Modifying annotation to indicate a modifying operation.

2. Step 2: Check parameter syntax and nativeQuery flag

   @Modifying @Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1", nativeQuery = true) int increasePriceByCategory(String category); correctly uses positional parameter ?1 and sets nativeQuery = true. @Modifying @Query(value = "UPDATE products SET price = price * 1.1 WHERE category = :category", nativeQuery = true) int increasePriceByCategory(String category); uses named parameter which is invalid in native queries. @Modifying @Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1") int increasePriceByCategory(String category); misses nativeQuery flag. @Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1", nativeQuery = true) void increasePriceByCategory(String category); misses @Modifying.

3. Final Answer:

   @Modifying @Query(value = "UPDATE products SET price = price * 1.1 WHERE category = ?1", nativeQuery = true) int increasePriceByCategory(String category); -> Option A

4. Quick Check:

   Update native queries need @Modifying and nativeQuery=true [OK]

Hint: Use @Modifying and nativeQuery=true for update queries [OK]

Common Mistakes:

• Omitting @Modifying on update queries
• Using named parameters in native queries
• Forgetting nativeQuery=true flag
• Returning void instead of int for update count