How to Compare Dates in MySQL ?

When working with dates in MySQL or working with MySQL compare dates, you should compare them to see which is older or newer. Fortunately, MySQL includes several date-comparison functions that can be useful in various circumstances.

The first thing you should learn is how MySQL stores dates. MySQL stores dates in the format YYYY-MM-DD, where YYYY is the year, MM is the month, and DD is the day. You must use a comparison operator such as <, >, =, or >= to compare two dates.

Assume you have a table called orders and a column called order_date containing dates in the format YYYY-MM-DD format.

Let's see how we can create such a table-

To find all orders placed after a specific date, use the >= operator as follows:

Output:

This would return all orders placed on or after January 1, 2022.

Similarly, to find all orders that were placed before a certain date, you could use the <= operator like this:

Output:

All orders placed on or before December 31, 2021, will be returned.

If you want to find all orders placed between two dates, use both the > and < operators, as shown below:

Output:

All orders placed between January 1, 2022, and December 31, 2021, will be returned.

It's critical to remember that when comparing dates, you should always use the proper date format and wrap the date in quotes. Otherwise, MySQL may be unable to compare the dates correctly.

To summarize, comparing dates in MySQL is a simple process. You can obtain the information from your database using relevant comparison operators and following the correct date format.

Overview of MySQL Date Data Types

For MySQL compare dates, it's critical to understand the various date data types available. MySQL supports numerous date data types, each with its properties and applications.

DATE, DATETIME, and TIMESTAMP are MySQL's most often used date data types. However, MySQL also includes several other date-related data types, such as YEAR, TIME, and INTERVAL, in addition to these. Each of these data types has unique applications and properties.

Finally, understanding MySQL's various date data types is critical for working effectively with dates. You may verify that your date values are stored and used correctly by selecting the suitable data type for your needs.

DATE

Dates in the format YYYY-MM-DD are stored in MySQL using the DATE data type. It can be extremely handy when working with apps that require date-related functionality, such as scheduling or recording events.

It is vital to realize that MySQL saves dates as strings rather than numbers or other data types. Therefore, when working with the DATE data type, you must use the right format and enclose the date in quotes.

When you create a table in MySQL, you can designate a column as a DATE data type, as seen below:

You can then insert values into the table using the correct date format, like this:

To retrieve the data from the table, you can use a SELECT statement like this:

This would return all rows where the my_date field equals May 1, 2022.

To demonstrate the DATE data type, here's a sample table and some data:

To retrieve all events that are scheduled before June 1, 2022, you can use the following query:

Output:

DATETIME

MySQL is a prominent open-source relational database management system that stores and manipulates data using various data types. For example, DATETIME is a data type that stores dates and times in a specified format.

DATETIME is a data type that combines DATE and TIME, allowing it to contain date and time information in a single column. For example, the DATETIME data type can contain dates ranging from January 1, 1000, to December 31, 9999, with a precision of up to six decimal places, representing fractions of a second.

When creating a table in MySQL, you can use the DATETIME data type to define a column that stores date and time values. For example:

In this example, the created_at column is defined as a DATETIME data type containing the date and time when a record is created in the my_table table.

You can use the SELECT statement to retrieve data from a DATETIME column and prepare the result with the DATE_FORMAT() function. As an example:

The id and created_at columns will be retrieved from the my_table table, and the created_at column will be formatted using the DATE_FORMAT() function to show the date and time values understandably.

TIMESTAMP

The TIMESTAMP data type in MySQL holds date and time values. It's a popular option because it's adaptable, efficient, and simple.

The number of seconds since the Unix epoch (January 1, 1970, at 00:00:00 UTC) is saved as a TIMESTAMP value. This means that TIMESTAMP values can indicate dates and times ranging from January 1, 1970, to 2038.

One advantage of TIMESTAMP is that it refreshes immediately whenever a record is inserted or changed. This can be handy for tracking data changes.

Another advantage of TIMESTAMP is that it can be indexed, allowing faster and more efficient queries.

To create a table and insert data with a TIMESTAMP column, you can use the following syntax:

To select data from the table, you can use a simple SELECT statement:

Output:

Finally, TIMESTAMP is a versatile and efficient data type that may be used in MySQL to store date and time values. Its automatic updating and indexing capabilities make it popular for various applications.

TIME

MySQL is a strong relational database management system that supports various data types to meet various requirements. TIME is one such data type used to record time information in the hours, minutes, and seconds format.

In MySQL, the TIME data type is expressed in the format HH:MM:SS, where HH represents hours, MM represents minutes, and SS represents seconds. This data typically comes in handy when storing and managing time values in your database, such as in scheduling applications, time-tracking systems, or other time-related duties.

Here's an example of a table that stores the duration of each task using the TIME data type:

To get the total time spent on all tasks in hours, use the SUM function in conjunction with the TIME_TO_SEC function, which converts the time value to seconds:

Output:

This query returns the total duration of all tasks in hours, which is 7 hours in this example.

Overall, MySQL's TIME data type is useful for storing and manipulating time values. This data type can let you easily manage and manipulate time values, whether you're creating a time-tracking system or a scheduling application.

YEAR

The YEAR uses one byte of storage space and may contain numbers ranging from 1901 to 2155. It is frequently used to record information like birth years or copyright dates, where just the year value is important.

In MySQL, you can use the following syntax to define a column as a YEAR data type.:

You can also specify a default value for the YEAR column using the DEFAULT keyword:

To insert values into a YEAR column, you can utilize the following syntax:

To retrieve the values stored in a YEAR column, you can utilize the SELECT statement:

Output:

To summarize, MySQL's YEAR data type is a quick and easy way to store year values. It can be used for everything from recording dates to organizing historical data.

Compare between Two Dates

MySQL compares dates utilizing the DATE type and the comparison mentioned above operations. For example:

1. You can use the following query to locate all records with a date greater than or equal to a specific date:

2. Similarly, to find all records that have a date less than or equal to a specified date, you can use the following query:

3. To find all records that have a date between two specified dates, you can use the following query:

Let's take an example table with some data to demonstrate how these queries work:

To find all sales made after March 1, 2022, you can use the following query:

Output:

Use the DATE_ADD Function

For MySQL to compare dates, we can also use the DATE_ADD function in MySQL allows you to add or subtract a given time interval from a date or datetime value. This function has many applications, from calculating due dates to anticipating future events.

The following is the syntax for utilizing the DATE_ADD function:

In this case, date refers to the date or datetime value to which the interval is added, value refers to the number of intervals to be added, and unit refers to the type of interval to be added, such as YEAR, MONTH, DAY, HOUR, MINUTE, or SECOND.

Assume you have a table called orders that contains order dates, and you want to add 30 days to each order date:

Output:

As you can see, the DATE_ADD function has added 30 days to each order date, resulting in the due date for each order. This is just one example of how to use MySQL's DATE_ADD function to manipulate date and datetime values.

Compare a DATE to NOW in MySQL

It is frequently important in MySQL to compare a date to the current date and time. This can be beneficial in various situations, such as detecting forthcoming events or verifying a product's expiration date.

In MySQL, you can use the NOW() function to compare a date to the current date and time. The function NOW() returns the current date and time in the format YYYY-MM-DD HH:MM:SS.

Here's an example table:

Here is an example query that compares a date column to the current date and time:

Output:

In this query, example_table is the table's name, and event_date is the column's name that holds the date to be compared. The query returns all rows where the event_date is after the current date and time.

Compare Dates with a Timestamp

When working with databases, comparing dates and timestamps is a common task. A timestamp is a data type in MySQL representing a date and time value. To compare dates and timestamps, ensure the date and timestamp formats are consistent.

In MySQL, one method for comparing dates and timestamps is to use the DATE() function to retrieve the date portion of the timestamp value.

Here is an example table for demonstration purposes:

Example-1:

Output:

This query will retrieve all orders placed on May 2, 2022, regardless of when the order was placed.

Example-2:

Output:

This query will return all orders placed between April 1, 2022, and April 30, 2022.

Finally, comparing dates and timestamps in MySQL is a simple procedure that can be achieved utilizing various methods and operators. Understanding these ideas will allow you to query your database and efficiently retrieve the data you require.