MySQL Datetime

Introduction to MySQL Datetime

The following article provides an outline for MySQL Datetime. If we want to store a value of date that contains both date and time in it. Then we use the Datetime format. The Datetime stores the data in the format of year, month, date, hour, minutes and seconds. The Datetime uses 5 bytes for storage. We can also store the fraction but storing the fraction would increase the storage. If we are considering precision and want to store the precision fraction(0)- takes 0 storage bytes. If for fraction (1 ,2) takes 1 byte. Fraction (3,4) takes 2 bytes and Fraction (5, 6) takes 3 bytes of storage. Total of 3 bytes would need extra for storage of fraction.

Syntax:

<column_name>datetime;

To define a column as datetime type we define as the above.

How does MySQL Datetime works?

Now let us create a table with a column data type as datetime and get the result.

Code:

CREATE TABLE TEST_DATETIME1
(
ORDER_ID VARCHAR(10),
ORDER_DATE DATETIME
);

Let us insert the data into the table:

Code:

INSERT INTO TEST_DATETIME1 VALUES ('O1','2019-01-01 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O2','2019-02-02 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O3','2019-03-03 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O4','2019-04-04 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O5','2019-05-05 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O6','2019-06-06 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O7','2019-07-07 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O8','2019-08-08 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O9','2019-09-09 12:00:00');
INSERT INTO TEST_DATETIME1 VALUES ('O10','2019-10-10 12:00:00');

select * from test_datetime1;

Output:

Here we check the data for the “order_date” we could see that the storage taken for the column is 7 bytes as it is saving the precision fraction of (3, 4).

If we see the value of “ Date_time “ value:

2019-01-01 12:00.00.000

Given below is the format of the above data:

yyyy-mm-ddhh:mm:ss:ff

• YYYY: Is year – 2019
• MM: Is month – 01
• DD: Is Date -01
• HH: Hour – 12
• MM: Month – 00
• SS: Second – 00
• FF: Fraction seconds – 000

As per the above example:

‘2019-01-01 12:00.00.000’

Code:

CREATE TABLE TEST_DT
(
SERIAL_NUMBER INT,
DATE_TIME DATETIME
);

Now let us insert into the table with the current date:

Code:

INSERT INTO TEST_DT VALUES (1,'2019-01-01 09:22:08:123');
INSERT INTO TEST_DT VALUES (2,'2019-01-02 10:22:08:123');
INSERT INTO TEST_DT VALUES (3,'2019-01-03 11:22:08:123');
INSERT INTO TEST_DT VALUES (4,'2019-01-04 12:22:08:123');
INSERT INTO TEST_DT VALUES (5,'2019-01-05 13:22:08:123');
INSERT INTO TEST_DT VALUES (6,'2019-01-06 14:22:08:123');
INSERT INTO TEST_DT VALUES (7,'2019-01-07 15:22:08:123');
INSERT INTO TEST_DT VALUES (8,'2019-01-08 16:22:08:123');
INSERT INTO TEST_DT VALUES (9,'2019-01-09 17:22:08:123');
INSERT INTO TEST_DT VALUES (10,'2019-01-10 18:22:08:123');
INSERT INTO TEST_DT VALUES (11,'2019-01-11 19:22:08:123');
INSERT INTO TEST_DT VALUES (12,'2019-01-12 20:22:08:123');

select * from TEST_DT

Output:

Here we check the data for the “order_date” we could see that the storage taken for the column is 7 bytes as it is saving the precision fraction of (3,4).

If we see the value of “ Date_time “ value:

2019-01-01 09:22.08.123

Given below is the format of the above data:

yyyy-mm-ddhh:mm:ss:ff

• YYYY: Is year – 2019
• MM: Is month – 01
• DD: Is Date – 01
• HH: Hour – 09
• MM: Month – 22
• SS: Second – 08
• FF: fraction seconds -123

Output:

Example of MySQL Datetime

Given below is the example mentioned:

Code:

CREATE TABLE TEST_DT1
(
SERIAL_NUMBER INT,
DATE_TIME DATETIME
);

Now let us insert into the table with the current date:

Code:

INSERT INTO TEST_DT1 VALUES (11,'2019-01-11 09:22:08:123');
INSERT INTO TEST_DT1 VALUES (22,'2019-01-12 10:22:08:123');
INSERT INTO TEST_DT1 VALUES (33,'2019-01-13 11:22:08:123');
INSERT INTO TEST_DT1 VALUES (44,'2019-01-14 12:22:08:123');
INSERT INTO TEST_DT1 VALUES (55,'2019-01-15 13:22:08:123');
INSERT INTO TEST_DT1 VALUES (66,'2019-01-16 14:22:08:123');
INSERT INTO TEST_DT1 VALUES (77,'2019-01-17 15:22:08:123');
INSERT INTO TEST_DT1 VALUES (88,'2019-01-18 16:22:08:123');
INSERT INTO TEST_DT1 VALUES (99,'2019-01-19 17:22:08:123');
INSERT INTO TEST_DT1 VALUES (110,'2019-01-21 18:22:08:123');
INSERT INTO TEST_DT1 VALUES (111,'2019-01-22 19:22:08:123');
INSERT INTO TEST_DT1 VALUES (122,'2019-01-23 20:22:08:123');


Select * from TEST_DT1;

Output:

Here if we check the data for the “Date_time” we could see that the storage taken for the column is 7 bytes as it is saving the precision fraction of (3, 4).

If we see the value of “ Date_time “ value:

2019-01-11 09:22.08.123

Given below is the format of the above data:

yyyy-mm-ddhh:mm:ss:ff

• YYYY: Is year – 2019
• MM: Is month – 01
• DD: Is Date – 11
• HH: Hour – 09
• MM: Month – 22
• SS: Second – 08
• FF: Fraction seconds – 123

Conclusion

If we want to store a value of date that contains both date and time in it then we use the Datetime format. The Datetime stores the data in the format of year, month, date, hour, minutes and seconds. The Datetime uses 5 bytes for storage. We can also store the fraction but storing the fraction would increase the storage. If we are considering precision and want to store the precision fraction (0)- takes 0 storage bytes. If for fraction (1, 2) takes 1 byte. Fraction (3, 4) takes 2 bytes and Fraction (5, 6) takes 3 bytes of storage. Total of 3 bytes would need extra for storage of fraction.

This is a guide to MySQL Datetime. Here we discuss the introduction to MySQL Datetime, how does it works with example respectively. You may also have a look at the following articles to learn more –

1. MySQL IN Operator
2. MySQL Subquery
3. ANY in MySQL
4. MySQL Self Join