Integer types (TINYINT, INT, BIGINT) in MySQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the range of values for a signed TINYINT in MySQL?

A signed TINYINT can store values from -128 to 127.

beginner

What is the difference between signed and unsigned integer types in MySQL?

Signed integers can store both negative and positive numbers, while unsigned integers can only store zero and positive numbers, effectively doubling the positive range.

beginner

How many bytes does a BIGINT use in MySQL?

A BIGINT uses 8 bytes of storage.

intermediate

What is the maximum value of an unsigned INT in MySQL?

The maximum value of an unsigned INT is 4,294,967,295.

intermediate

Why would you choose BIGINT over INT in a database column?

You choose BIGINT when you need to store very large integer values that exceed the range of INT, such as very large counts or IDs.

Which integer type uses the least storage space in MySQL?

A TINYINT

B INT

C BIGINT

D SMALLINT

TINYINT uses 1 byte, which is less than INT (4 bytes) and BIGINT (8 bytes).

What is the maximum value of a signed INT in MySQL?

A 2,147,483,647

B 4,294,967,295

C 127

D 9,223,372,036,854,775,807

A signed INT ranges from -2,147,483,648 to 2,147,483,647.

How many bytes does an INT use in MySQL?

A 2 bytes

B 4 bytes

C 1 byte

D 8 bytes

INT uses 4 bytes of storage.

Which integer type can store the largest positive number in MySQL?

A TINYINT

B INT

C BIGINT

D SMALLINT

BIGINT can store the largest positive number because it uses 8 bytes.

What happens if you insert a value larger than the maximum allowed in a TINYINT column?

A The value is stored correctly

B The value is automatically converted to BIGINT

C The value is stored as NULL

D MySQL throws an error or truncates the value

MySQL throws an error or truncates the value to the maximum allowed for the column type.

Explain the differences between TINYINT, INT, and BIGINT in MySQL including their storage size and value ranges.

Think about how much space each type uses and how big the numbers can be.

Why is it important to choose the correct integer type for a database column?

Consider what happens if the number is too big or too small for the chosen type.

Practice

1. Which MySQL integer type should you use to store a small number between 0 and 255 efficiently?

easy

A. BIGINT

B. INT

C. TINYINT

D. SMALLINT

Solution

1. Step 1: Understand the range of TINYINT and compare with other types

   TINYINT can store values from 0 to 255 when unsigned, which fits small numbers efficiently. INT and BIGINT store much larger numbers but use more space. SMALLINT also uses more space unnecessarily.

2. Final Answer:

   TINYINT -> Option C

3. Quick Check:

   Small numbers (0-255) = TINYINT [OK]

Hint: Use TINYINT for numbers up to 255 to save space [OK]

Common Mistakes:

• Choosing INT for small numbers wastes space
• Confusing TINYINT with SMALLINT
• Not considering unsigned range

2. Which of the following is the correct syntax to declare a NOT NULL BIGINT column named user_id in MySQL?

easy

A. user_id BIGINT;

B. BIGINT user_id;

C. user_id INT BIG;

D. user_id BIGINT NOT NULL;

Solution

1. Step 1: Check correct order of declaration

   In MySQL, the column name comes first, then the data type, optionally followed by constraints like NOT NULL. Only A follows this: user_id BIGINT NOT NULL;.

2. Final Answer:

   user_id BIGINT NOT NULL; -> Option D

3. Quick Check:

   Column name + type + constraints = correct syntax [OK]

Hint: Column name first, then type, then constraints [OK]

Common Mistakes:

• Putting type before column name
• Using invalid order of keywords
• Missing semicolon in some contexts

3. Given the table orders with a column order_count TINYINT UNSIGNED, what will be the result of this query?

INSERT INTO orders (order_count) VALUES (300);
SELECT order_count FROM orders;

medium

A. 300

B. Error: Out of range value

C. 0

D. 44

Solution

1. Step 1: Understand TINYINT UNSIGNED range and insert effect

   TINYINT UNSIGNED stores 0-255 only. 300 exceeds range, so INSERT throws 'Error: Out of range value' (default strict mode).

2. Final Answer:

   Error: Out of range value -> Option B

3. Quick Check:

   Value > 255 in TINYINT UNSIGNED causes error [OK]

Hint: Check value fits type range before insert [OK]

Common Mistakes:

• Assuming values wrap around silently
• Ignoring unsigned range limits
• Expecting automatic truncation without error

4. You have a column defined as INT but you want to store numbers larger than 4,294,967,295. Which change fixes the problem?

medium

A. Change the column type to BIGINT

B. Change the column type to TINYINT

C. Add UNSIGNED to the INT column

D. Use VARCHAR instead of INT

Solution

1. Step 1: Understand INT range limits and select proper type

   Signed INT max ~2.1 billion, UNSIGNED INT max 4,294,967,295. BIGINT handles much larger (up to ~9 quintillion).

2. Final Answer:

   Change the column type to BIGINT -> Option A

3. Quick Check:

   BIGINT stores bigger numbers than INT [OK]

Hint: Use BIGINT for numbers bigger than INT max [OK]

Common Mistakes:

• Using TINYINT which is smaller
• Adding UNSIGNED but still too small
• Switching to VARCHAR loses numeric benefits

5. You want to store user scores that can be very large, but you also want to save space when scores are small. Which MySQL integer type strategy is best?

hard

A. Use INT for most scores and BIGINT only if scores exceed INT range

B. Use TINYINT and switch to BIGINT if needed later

C. Always use BIGINT for all scores

D. Use BIGINT but compress data manually

Solution

1. Step 1: Balance storage and range needs

   TINYINT too small; always BIGINT wastes space. Use INT initially (efficient for small/medium), ALTER to BIGINT later if needed.

2. Final Answer:

   Use INT for most scores and BIGINT only if scores exceed INT range -> Option A

3. Quick Check:

   Balance size and range with INT then BIGINT [OK]

Hint: Start with INT, upgrade to BIGINT if needed [OK]

Common Mistakes:

• Always using BIGINT wastes space
• Starting with TINYINT causes overflow
• Manual compression is complex and error-prone