Fetching the Top Records with LIMIT

In many real-world applications, you might only need to display a subset of results from a database query, such as the latest entries, the top-selling products, or the first few users who signed up. The LIMIT clause in SQL is a powerful tool for achieving this, allowing you to control the number of rows returned by a query. This challenge will test your understanding of how to effectively use LIMIT to retrieve a specific number of records.

Problem Description

Your task is to write a SQL query that retrieves a specified number of records from a given table. You will be provided with the name of a table and an integer representing the maximum number of records to return. The query should return the first N records from the table, where N is the specified limit. If the table contains fewer than N records, the query should return all available records.

Key Requirements:

• Use the LIMIT clause in your SQL query.
• The query should return exactly N rows if the table has N or more rows.
• If the table has fewer than N rows, the query should return all rows.

Expected Behavior: The query should fetch and display the specified number of records from the beginning of the dataset. The order of records in the output will depend on the default ordering of the table or any explicit ORDER BY clause (though for this challenge, assume no ORDER BY is explicitly required unless specified in examples).

Edge Cases:

• What happens if the table is empty?
• What happens if the limit is 0?

Examples

Example 1:

Table: products
Columns: product_id (INT), product_name (VARCHAR), price (DECIMAL)
Limit: 3

SELECT *
FROM products
LIMIT 3;

Output:

product_id | product_name | price
-----------|--------------|-------
1          | Laptop       | 1200.00
2          | Keyboard     | 75.00
3          | Mouse        | 25.00

Explanation: This query returns the first 3 rows from the products table.

Example 2:

Table: users
Columns: user_id (INT), username (VARCHAR), registration_date (DATE)
Limit: 10

SELECT *
FROM users
LIMIT 10;

Output: (Assuming the users table has 5 rows)

user_id | username | registration_date
--------|----------|-------------------
101     | alice    | 2023-01-15
102     | bob      | 2023-02-20
103     | charlie  | 2023-03-10
104     | david    | 2023-04-05
105     | eve      | 2023-05-22

Explanation: The users table has only 5 records, which is less than the specified limit of 10. Therefore, the query returns all 5 available records.

Example 3 (Edge Case):

Table: orders
Columns: order_id (INT), customer_id (INT), order_date (DATE)
Limit: 0

SELECT *
FROM orders
LIMIT 0;

Output: (An empty set of results) Explanation: A LIMIT of 0 typically returns an empty result set, indicating no rows should be fetched.

Constraints

• The table name will be a valid string.
• The limit value will be a non-negative integer (>= 0).
• The maximum value for the limit will not exceed 1000.
• Assume standard SQL syntax compatible with most RDBMS.
• The database will contain at least one table with sample data for testing.

Notes

• The LIMIT clause is a standard SQL feature, but its exact syntax might slightly vary across different database systems (e.g., TOP N in SQL Server). For this challenge, use the common LIMIT N syntax.
• While not explicitly required for this challenge, in real-world scenarios, you would often combine LIMIT with an ORDER BY clause to ensure you are fetching a consistent and meaningful subset of data (e.g., the top 10 highest scores).