Writing SQL CASE Statements for Cross-Platform Compatibility

Writing a Query that uses CASE Statements Across Databases

Write a SQL query to categorize employees by salary range using CASE statements, ensuring compatibility across MySQL, PostgreSQL, and SQL Server.

Solution:

-- Compatible across MySQL, PostgreSQL, and SQL Server
SELECT EmployeeID, Name, Salary,
       CASE
           WHEN Salary < 30000 THEN 'Low'
           WHEN Salary BETWEEN 30000 AND 70000 THEN 'Medium'
           ELSE 'High'
       END AS SalaryCategory
FROM Employees;

Explanation:

• Purpose of the Query :
• The goal is to demonstrate how CASE statements work consistently across database systems.
• Key Components :
• CASE: Categorizes employees based on salary ranges.
• WHEN and ELSE: Define conditions and default values.
• Why Use CASE Statements?:
• CASE statements are widely supported and simplify conditional logic.
• They ensure consistent behavior across platforms.
• Real-World Application :
• In HR systems, categorizing salaries supports budgeting and analysis.

Additional Notes:

• Use CASE statements for cross-platform compatibility.
• Test queries on all target platforms to ensure consistent results.
• Important Considerations:
• Avoid overly complex CASE logic for readability.

For more Practice: Solve these Related Problems:

• Write a SQL query to categorize products by price range using CASE statements, ensuring compatibility across MySQL, PostgreSQL, and SQL Server.
• Write a SQL query to categorize students by grade using CASE statements, ensuring compatibility across MySQL, PostgreSQL, and SQL Server.
• Write a SQL query to categorize orders by status using CASE statements, ensuring compatibility across MySQL, PostgreSQL, and SQL Server.
• Write a SQL query to categorize employees by experience level using CASE statements, ensuring compatibility across MySQL, PostgreSQL, and SQL Server.

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