LIMIT vs TOP vs FETCH FIRST syntax in SQL - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select the first 5 rows using LIMIT syntax.

SQL

SELECT * FROM employees [1] 5;

Drag options to blanks, or click blank then click option'

ALIMIT

BTOP

CFETCH FIRST

DWHERE

Attempts:

3 left

💡 Hint

Common Mistakes

Using TOP instead of LIMIT in MySQL or PostgreSQL.

Placing LIMIT before FROM clause.

The LIMIT keyword is used in SQL dialects like MySQL and PostgreSQL to restrict the number of rows returned.

2fill in blank

medium

Complete the code to select the top 3 rows using TOP syntax.

SQL

SELECT [1] 3 * FROM sales;

Drag options to blanks, or click blank then click option'

AFETCH FIRST

BLIMIT

CTOP

DWHERE

Attempts:

3 left

💡 Hint

Common Mistakes

Using LIMIT instead of TOP in SQL Server.

Placing TOP after FROM clause.

The TOP keyword is used in SQL Server to get the first N rows.

3fill in blank

hard

Fix the error in the FETCH FIRST syntax to select 10 rows.

SQL

SELECT * FROM orders [1] 10 ROWS ONLY;

Drag options to blanks, or click blank then click option'

ALIMIT

BTOP

CFETCH NEXT

DFETCH FIRST

Attempts:

3 left

💡 Hint

Common Mistakes

Using LIMIT or TOP keywords with FETCH FIRST syntax.

Omitting ROWS ONLY at the end.

The correct syntax to limit rows in standard SQL is FETCH FIRST N ROWS ONLY.

4fill in blank

hard

Fill both blanks to select 7 rows using FETCH FIRST syntax.

SQL

SELECT * FROM products ORDER BY price [1] 7 [2] ONLY;

Drag options to blanks, or click blank then click option'

AFETCH FIRST

BROWS

CROW

DLIMIT

Attempts:

3 left

💡 Hint

Common Mistakes

Using LIMIT instead of FETCH FIRST.

Using ROW instead of ROWS for multiple rows.

The standard syntax is FETCH FIRST N ROWS ONLY to limit rows.

5fill in blank

hard

Fill all three blanks to select top 4 rows using TOP syntax with alias.

SQL

SELECT [1] 4 [2] FROM sales_data AS top_sales [3];

Drag options to blanks, or click blank then click option'

ATOP

B*

CWHERE sales > 1000

DLIMIT

Attempts:

3 left

💡 Hint

Common Mistakes

Using LIMIT instead of TOP in SQL Server.

Omitting the WHERE clause when filtering is needed.

Use TOP after SELECT, then columns (like *), and optionally a WHERE clause for filtering.

Practice

1. Which SQL clause is used to limit the number of rows returned in a query in MySQL and PostgreSQL?

easy

A. LIMIT

B. TOP

C. FETCH FIRST

D. ROWNUM

Solution

1. Step 1: Identify the database systems mentioned

   MySQL and PostgreSQL use the LIMIT clause to restrict rows.

2. Step 2: Match the clause to the database

   TOP is for SQL Server, FETCH FIRST is for Oracle and others, ROWNUM is Oracle-specific but older style.

3. Final Answer:

   LIMIT -> Option A

4. Quick Check:

   MySQL/PostgreSQL use LIMIT [OK]

Hint: MySQL/PostgreSQL use LIMIT to restrict rows [OK]

Common Mistakes:

• Confusing TOP with LIMIT
• Using FETCH FIRST in MySQL
• Using ROWNUM in PostgreSQL

2. Which of the following is the correct syntax to get the top 5 rows in SQL Server?

easy

A. SELECT * FROM table WHERE ROWNUM <= 5;

B. SELECT * FROM table LIMIT 5;

C. SELECT * FROM table FETCH FIRST 5 ROWS ONLY;

D. SELECT TOP 5 * FROM table;

Solution

1. Step 1: Identify SQL Server syntax for limiting rows

   SQL Server uses TOP n after SELECT to limit rows.

2. Step 2: Check each option

   SELECT * FROM table LIMIT 5; uses LIMIT (MySQL/PostgreSQL), SELECT * FROM table FETCH FIRST 5 ROWS ONLY; uses FETCH FIRST (Oracle), SELECT * FROM table WHERE ROWNUM <= 5; uses ROWNUM (Oracle). Only SELECT TOP 5 * FROM table; is correct for SQL Server.

3. Final Answer:

   SELECT TOP 5 * FROM table; -> Option D

4. Quick Check:

   SQL Server uses TOP [OK]

Hint: TOP goes right after SELECT in SQL Server [OK]

Common Mistakes:

• Using LIMIT in SQL Server
• Placing TOP after FROM
• Using FETCH FIRST in SQL Server

3. Given this query in Oracle:

SELECT * FROM employees FETCH FIRST 3 ROWS ONLY;

What will be the result?

medium

A. Syntax error because FETCH FIRST is not valid in Oracle

B. Returns the first 3 rows from employees

C. Returns all rows because FETCH FIRST is ignored

D. Returns 3 random rows from employees

Solution

1. Step 1: Understand FETCH FIRST in Oracle

   Oracle supports FETCH FIRST n ROWS ONLY to limit rows returned.

2. Step 2: Determine query behavior

   The query returns exactly the first 3 rows from the employees table as ordered by the query (default order if none specified).

3. Final Answer:

   Returns the first 3 rows from employees -> Option B

4. Quick Check:

   Oracle FETCH FIRST limits rows [OK]

Hint: FETCH FIRST limits rows in Oracle [OK]

Common Mistakes:

• Thinking FETCH FIRST causes syntax error in Oracle
• Assuming FETCH FIRST returns random rows
• Believing FETCH FIRST is ignored

4. Identify the error in this SQL Server query:

SELECT * FROM customers FETCH FIRST 10 ROWS ONLY;

medium

A. Should use LIMIT instead of FETCH FIRST

B. Missing ORDER BY clause with FETCH FIRST

C. FETCH FIRST is not supported in SQL Server

D. Syntax is correct, no error

Solution

1. Step 1: Check FETCH FIRST support in SQL Server

   SQL Server does not support FETCH FIRST; it uses TOP instead.

2. Step 2: Analyze other options

   Missing ORDER BY clause with FETCH FIRST is incorrect because FETCH FIRST requires ORDER BY in some databases but SQL Server does not support FETCH FIRST at all. Should use LIMIT instead of FETCH FIRST is wrong because SQL Server uses TOP, not LIMIT. Syntax is correct, no error is false because syntax is invalid.

3. Final Answer:

   FETCH FIRST is not supported in SQL Server -> Option C

4. Quick Check:

   SQL Server uses TOP, not FETCH FIRST [OK]

Hint: SQL Server uses TOP, not FETCH FIRST [OK]

Common Mistakes:

• Using FETCH FIRST in SQL Server
• Confusing LIMIT with FETCH FIRST
• Assuming FETCH FIRST works without ORDER BY

5. You want to write a query that returns the top 10 rows from a table named sales in a database that supports both FETCH FIRST and LIMIT. Which query is correct and why?

Options:
A) SELECT * FROM sales LIMIT 10;
B) SELECT * FROM sales FETCH FIRST 10 ROWS ONLY;
C) SELECT TOP 10 * FROM sales;
D) SELECT * FROM sales WHERE ROWNUM <= 10;

hard

A. Correct if the database supports LIMIT syntax

B. Correct if the database supports FETCH FIRST syntax

C. Correct only in SQL Server

D. Correct only in Oracle with ROWNUM

Solution

1. Step 1: Understand the database supports both FETCH FIRST and LIMIT

   Some modern databases like DB2 or Oracle 12c+ support FETCH FIRST, while others like MySQL use LIMIT.

2. Step 2: Choose the correct syntax for the database

   If the database supports both, FETCH FIRST is the ANSI standard and preferred for portability. LIMIT is not standard SQL. TOP is SQL Server specific, and ROWNUM is Oracle-specific older syntax.

3. Final Answer:

   SELECT * FROM sales FETCH FIRST 10 ROWS ONLY; -> Option A

4. Quick Check:

   FETCH FIRST is ANSI standard for limiting rows [OK]

Hint: Use FETCH FIRST for ANSI standard row limiting [OK]

Common Mistakes:

• Using TOP in non-SQL Server databases
• Assuming LIMIT is standard SQL
• Using ROWNUM outside Oracle