Retrieve All Records from a Database Table
You are tasked with building a fundamental SQL query that retrieves every single record from a given database table. This is a foundational operation in data management, essential for tasks like data inspection, backups, and populating reports.
Problem Description
Your goal is to write a SQL SELECT statement that fetches all columns and all rows from a specified table.
What needs to be achieved:
- Construct a SQL query that returns all data from a table.
Key requirements:
- The query must select all columns.
- The query must select all rows.
- The query must be syntactically correct SQL.
Expected behavior:
- The query should return a result set containing every row and every column from the target table.
Important edge cases to consider:
- What happens if the table is empty?
Examples
Example 1:
Input:
Assume a table named customers with the following structure and data:
| customer_id | first_name | last_name | |
|---|---|---|---|
| 1 | Alice | Smith | alice.s@email.com |
| 2 | Bob | Johnson | bob.j@email.com |
| 3 | Charlie | Brown | charlie.b@email.com |
Output:
SELECT * FROM customers;
Explanation:
The query SELECT * FROM customers; selects all columns (*) and all rows from the customers table. The output will be the entire table as shown in the input.
Example 2:
Input:
Assume a table named products with the following structure and data:
| product_id | product_name | price |
|---|---|---|
| 101 | Laptop | 1200 |
| 102 | Keyboard | 75 |
Output:
SELECT * FROM products;
Explanation:
The query SELECT * FROM products; retrieves all records from the products table.
Example 3: Empty Table
Input:
Assume a table named orders with the following structure but no data:
| order_id | customer_id | order_date | total_amount |
|---|
Output:
SELECT * FROM orders;
Explanation:
Even if the orders table is empty, the query SELECT * FROM orders; is still the correct way to attempt to retrieve all records. The output will be an empty result set.
Constraints
- The table name will be a valid identifier and will exist in the database.
- The query must be a single SQL
SELECTstatement. - The query should not include any
WHERE,ORDER BY,GROUP BY, orLIMITclauses.
Notes
This challenge is designed to test your understanding of the most basic SQL query for data retrieval. Remember that the asterisk (*) is a wildcard character in SQL SELECT statements.