Prevent Query Re-compilation with Parameterized Queries

Using Parameterized Queries to Prevent Re-compilation

Write a SQL query to use parameterized queries for consistent execution plans.

Solution:

-- Use a parameterized query to prevent re-compilation.
DECLARE @Department NVARCHAR(50) = 'HR';

SELECT EmployeeID, Name
FROM Employees
WHERE Department = @Department;

Explanation:

• Purpose of the Query :
• The goal is to demonstrate how parameterized queries reuse execution plans, reducing re-compilation overhead.
• Key Components :
• @Department: A parameter used in the query.
• Prevents the query optimizer from generating a new plan for each execution.
• Why use Parameterized Queries? :
• Parameterized queries improve performance by reusing cached execution plans.
• They also protect against SQL injection attacks.
• Real-World Application :
• In web applications, parameterized queries handle user inputs securely and efficiently.

Notes:

• Always use parameterized queries in application code to prevent SQL injection.
• Monitor plan cache usage to ensure effective reuse.
• Important Considerations:
• Avoid dynamic SQL unless absolutely necessary.

For more Practice: Solve these Related Problems:

• Write a SQL query to retrieve all orders placed by a specific customer using a parameterized query to prevent re-compilation.
• Write a SQL query to filter employees based on their department using a parameterized query for consistent execution plans.
• Write a SQL query to search for products within a price range using parameterized inputs to avoid SQL injection risks.
• Write a SQL query to fetch sales data for a given date range using parameterized queries for better performance and security.

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