Efficient Data Retrieval using Indexed Columns in MySQL

Optimize Query with WHERE Clause using Indexed Column

Write a MySQL query to retrieve all orders for a specific customer from the Orders table, ensuring query optimization by using indexed columns.

Solution:

-- Retrieve orders for customer 'ALFKI' using the CustomerID column.
SELECT * FROM Orders WHERE CustomerID = 'ALFKI';

Explanation:

• Purpose of the Query:
• To fetch orders for a specific customer efficiently.
• Demonstrates the benefit of having an index on the CustomerID column.
• Key Components:
• SELECT * FROM Orders : Retrieves all columns from the Orders table.
• WHERE CustomerID = 'ALFKI' : Filters orders by the customer identifier.
• Real-World Application:
• Commonly used in customer management systems where fast retrieval of customer orders is crucial.

Notes:

• Ensure that an index exists on CustomerID to make the query execution faster.
• The effectiveness of this query heavily relies on the indexing strategy.

For more Practice: Solve these Related Problems:

• Write a MySQL query to retrieve all products with a price greater than 100, ensuring query optimization by using indexed columns.
• Write a MySQL query to retrieve all users whose email starts with "admin", ensuring query optimization by using indexed columns.
• Write a MySQL query to retrieve all orders placed in the last week, ensuring query optimization by using indexed columns.
• Write a MySQL query to retrieve all employees in a specific department, ensuring query optimization by using indexed columns.

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous MySQL Exercise: Add an Index for Query Optimization.
Next MySQL Exercise: Remove an unused Index.