In SQL query writing, explain how you can limit or restrict the number of rows that are retrieved by a SELECT statement, including typical clauses and techniques.

Introduction / Context:
In practical database applications, you rarely want to retrieve every row from a table. Instead, you restrict results to the subset of data that matters, for example recent orders, the first ten products, or customers from a specific city. This question asks how SQL lets you control and limit the number of rows returned by a SELECT query, which is a key skill for performance and usability.

Given Data / Assumptions:

• We are writing SELECT statements against relational databases.
• The database may be Oracle, SQL Server, PostgreSQL, MySQL, or another vendor with similar features.
• We want to limit both which rows qualify and how many rows are finally returned.
• Standard SQL features such as WHERE, ORDER BY, and FETCH are available, and some platforms add vendor specific syntax.

Concept / Approach:
There are two levels of limiting rows. First, you filter rows logically using the WHERE clause so only rows meeting certain conditions are considered. Second, you can cap the number of rows returned using syntax such as LIMIT in MySQL and PostgreSQL, TOP in SQL Server, ROWNUM in older Oracle styles, or FETCH FIRST n ROWS ONLY in more standard SQL. Combining ordering with row limiting allows you to implement paging, top n reports, and dashboards efficiently.

Step-by-Step Solution:
Step 1: Use a WHERE clause to filter rows by conditions such as status = 'ACTIVE' or order_date >= some date, which removes rows that do not match.Step 2: Add ORDER BY to control the sequence of results, for example ordering by order_date descending.Step 3: Apply a row limiting clause appropriate for your database, such as LIMIT 10 in MySQL or FETCH FIRST 10 ROWS ONLY in Oracle and PostgreSQL, so only the first ten rows are returned after ordering.Step 4: In SQL Server, use SELECT TOP 10 columns FROM table ORDER BY some_column to achieve the same effect.Step 5: In Oracle legacy code you may see WHERE ROWNUM <= 10 to restrict the number of rows in the result set.

Verification / Alternative check:
To verify, run a query without any limit clause and observe that many rows are returned. Then add a row limiting clause such as LIMIT 5 or FETCH FIRST 5 ROWS ONLY and see that only five rows appear. Adjusting the limit value changes the result size immediately, confirming that the clause is controlling the output count without altering the underlying data.

Why Other Options Are Wrong:
Option B suggests deleting data, which is dangerous and unnecessary for query level limiting. Option C claims that SQL cannot limit rows, which is false because every major database supports this. Option D wrongly asserts that you must create a view, even though WHERE and FETCH clauses already provide this functionality inside a single SELECT statement.

Common Pitfalls:
A common mistake is using a limit without ORDER BY, which leads to unpredictable rows in the result set. Another pitfall is assuming that LIMIT without filtering is efficient when the table is very large. Combining proper indexes, conditions, and row limiting clauses is essential for scalable query performance.

Final Answer:
You can limit rows using clauses such as WHERE to filter records, ORDER BY combined with LIMIT or FETCH FIRST n ROWS ONLY, and in some databases by using ROWNUM or TOP to restrict the final row count.