DATE_FORMAT and EXTRACT in SQL

Introduction

We use DATE_FORMAT and EXTRACT to get parts of dates or show dates in a way that is easy to understand.

When you want to show a date as 'day-month-year' instead of the default format.

When you need to find the year or month from a date to group or filter data.

When you want to display the time part of a date in a special way.

When you want to calculate how many days or months have passed since a date.

When you want to sort or compare dates by parts like year or day.

Syntax

SQL

DATE_FORMAT(date, format)
EXTRACT(part FROM date)

DATE_FORMAT changes how a date looks using format codes like %Y for year, %m for month, %d for day.

EXTRACT gets one part of a date like year, month, day, hour, minute, or second.

Examples

Shows the date as day/month/year like 15/06/2024.

SQL

SELECT DATE_FORMAT('2024-06-15', '%d/%m/%Y');

Gets the year part from the date, which is 2024.

SQL

SELECT EXTRACT(YEAR FROM DATE('2024-06-15'));

Shows the current time as hours:minutes:seconds.

SQL

SELECT DATE_FORMAT(NOW(), '%H:%i:%s');

Gets the month part from the date, which is 6.

SQL

SELECT EXTRACT(MONTH FROM DATE('2024-06-15'));

Sample Program

This query shows the date in a friendly format and also extracts the year, month, and day parts separately.

SQL

SELECT
  DATE_FORMAT('2024-12-25', '%W, %M %d, %Y') AS formatted_date,
  EXTRACT(YEAR FROM DATE('2024-12-25')) AS year_part,
  EXTRACT(MONTH FROM DATE('2024-12-25')) AS month_part,
  EXTRACT(DAY FROM DATE('2024-12-25')) AS day_part;

Important Notes

DATE_FORMAT is very useful for showing dates in reports or user interfaces.

EXTRACT helps when you want to filter or group data by parts of a date.

Remember that format codes in DATE_FORMAT are case sensitive and must be used correctly.

Summary

DATE_FORMAT changes how a date looks using special codes.

EXTRACT gets one part of a date like year, month, or day.

Both help you work with dates in ways that fit your needs.

Practice

1. What does the SQL function EXTRACT(MONTH FROM '2024-06-15') return?

easy

A. '2024-06-15'

B. 15

C. 2024

D. 6

Solution

1. Step 1: Understand EXTRACT function

   The EXTRACT function pulls out a specific part of a date, here the MONTH part.

2. Step 2: Apply EXTRACT to the date

   From the date '2024-06-15', the month is 6 (June).

3. Final Answer:

   6 -> Option D

4. Quick Check:

   EXTRACT(MONTH FROM date) = 6 [OK]

Hint: EXTRACT pulls one date part, like month or year [OK]

Common Mistakes:

• Confusing day with month
• Expecting full date instead of part
• Using wrong syntax for EXTRACT

2. Which of the following is the correct syntax to get the year from a date using EXTRACT in SQL?

easy

A. EXTRACT(YEAR FROM '2024-06-15')

B. EXTRACT YEAR FROM '2024-06-15'

C. EXTRACT('YEAR', '2024-06-15')

D. EXTRACT('2024-06-15' FROM YEAR)

Solution

1. Step 1: Recall EXTRACT syntax

   The correct syntax is EXTRACT(part FROM date), with parentheses and FROM keyword.

2. Step 2: Check each option

   EXTRACT(YEAR FROM '2024-06-15') matches the correct syntax: EXTRACT(YEAR FROM '2024-06-15'). Others miss parentheses or have wrong order.

3. Final Answer:

   EXTRACT(YEAR FROM '2024-06-15') -> Option A

4. Quick Check:

   Correct EXTRACT syntax uses parentheses and FROM [OK]

Hint: EXTRACT needs parentheses and FROM keyword [OK]

Common Mistakes:

• Omitting parentheses
• Swapping arguments order
• Using quotes around part name

3. What is the output of this SQL query?

SELECT DATE_FORMAT('2024-06-15', '%Y-%m-%d'), EXTRACT(DAY FROM '2024-06-15');

medium

A. 2024-06-15, 6

B. 2024-06-15, 15

C. 2024/06/15, 15

D. 06-15-2024, 15

Solution

1. Step 1: Understand DATE_FORMAT with '%Y-%m-%d'

   This format outputs year-month-day as '2024-06-15'.

2. Step 2: Understand EXTRACT(DAY FROM date)

   Extracting DAY from '2024-06-15' gives 15.

3. Final Answer:

   2024-06-15, 15 -> Option B

4. Quick Check:

   DATE_FORMAT + EXTRACT day = '2024-06-15', 15 [OK]

Hint: DATE_FORMAT '%Y-%m-%d' matches original date format [OK]

Common Mistakes:

• Mixing month and day order
• Wrong format string in DATE_FORMAT
• Extracting wrong date part

4. Identify the error in this SQL query:

SELECT DATE_FORMAT('2024-06-15', '%Y-%d-%m');

medium

A. The date string must be in MM-DD-YYYY format

B. DATE_FORMAT requires three arguments

C. The format string swaps day and month incorrectly

D. EXTRACT should be used instead of DATE_FORMAT

Solution

1. Step 1: Analyze the format string '%Y-%d-%m'

   This format prints year, then day, then month, which is unusual and likely a mistake.

2. Step 2: Understand common date format order

   Usually, month comes before day as '%Y-%m-%d'. Swapping day and month causes confusing output.

3. Final Answer:

   The format string swaps day and month incorrectly -> Option C

4. Quick Check:

   Correct order is year-month-day, not year-day-month [OK]

Hint: Check format order: month before day usually [OK]

Common Mistakes:

• Mixing day and month in format string
• Wrong number of arguments to DATE_FORMAT
• Confusing DATE_FORMAT with EXTRACT

5. You want to list all orders from a table orders showing only the year and month of the order date in format YYYY-MM. Which SQL query correctly does this?

hard

A. SELECT DATE_FORMAT(order_date, '%Y-%m') AS year_month FROM orders;

B. SELECT EXTRACT(YEAR_MONTH FROM order_date) AS year_month FROM orders;

C. SELECT DATE_FORMAT(order_date, '%Y-%d') AS year_month FROM orders;

D. SELECT EXTRACT(MONTH FROM order_date) AS year_month FROM orders;

Solution

1. Step 1: Understand DATE_FORMAT for year and month

   Using '%Y-%m' in DATE_FORMAT returns year and month as 'YYYY-MM'.

2. Step 2: Check other options

   SELECT EXTRACT(YEAR_MONTH FROM order_date) AS year_month FROM orders; is invalid syntax; EXTRACT does not support YEAR_MONTH. SELECT DATE_FORMAT(order_date, '%Y-%d') AS year_month FROM orders; uses day instead of month. SELECT EXTRACT(MONTH FROM order_date) AS year_month FROM orders; returns only month number, missing year.

3. Final Answer:

   SELECT DATE_FORMAT(order_date, '%Y-%m') AS year_month FROM orders; -> Option A

4. Quick Check:

   DATE_FORMAT with '%Y-%m' gives year-month [OK]

Hint: Use DATE_FORMAT with '%Y-%m' for year and month [OK]

Common Mistakes:

• Using EXTRACT with unsupported parts
• Mixing day and month in format
• Selecting only month without year