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.
Go to:
PREV : Add an Index for Query Optimization.
NEXT : Remove an unused Index.
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