Oracle INTERVAL

Summary: in this tutorial, you’ll learn about the Oracle INTERVAL data types and how to handle intervals effectively.

Introduction to Oracle interval data type #

In Oracle, the INTERVAL data type allows you to store a specific period of time between two date time values. In other words, when you subtract two date time values, you’ll get an interval.

Oracle supports two types of intervals:

• INTERVAL YEAR TO MONTH – stores intervals using year and month.
• INTERVAL DAY TO SECOND – stores intervals using days, hours, minutes, and seconds including fractional seconds.

INTERVAL YEAR TO MONTH #

The INTERVAL YEAR TO MONTH data type represents a period in years and month such as 1 year 3 months.

Here’s the syntax of INTERVAL YEAR TO MONTH data type:

INTERVAL YEAR [(year_precision)] TO MONTHCode language: SQL (Structured Query Language) (sql)

The year_precision represents the number of digits in the YEAR field. It ranges from 0 to 9. It means you can use the INTERVAL YEAR TO MONTH data type to store up to 999,999,999 years.

The year_precision is optional. If you omit the year_precision argument, it defaults to 2. In other words, you can store up to a period of 99 years and 11 months by default, which must be less than 100 years.

INTERVAL YEAR TO MONTH literals #

To define literal values for the INTERVAL YEAR TO MONTH data type, you use the following format:

INTERVAL 'year[-month]' YEAR(precision) TO MONTHCode language: SQL (Structured Query Language) (sql)

In this syntax:

'year[-month]' is a string that represent the year and month for the leading and trailing fields of the interval.

For example, the following represents an interval of 10 years 2 months:

INTERVAL '10-2' YEAR TO MONTHCode language: JavaScript (javascript)

precision is the maximum number of digits in the year field. The precision ranges from 0 to 9. The default value is 2.

The following table illustrates examples of INTERVAL YEAR TO MONTH literals:

Oracle INTERVAL YEAR TO MONTH example #

First, create a new table calledcandidates for the demonstration:

CREATE TABLE candidates (
  candidate_id NUMBER GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  first_name VARCHAR2 (50) NOT NULL,
  last_name VARCHAR2 (50) NOT NULL,
  job_title VARCHAR2 (255) NOT NULL,
  year_of_experience INTERVAL YEAR TO MONTH
);Code language: SQL (Structured Query Language) (sql)

In this table, we have the year_of_experience column with the data type is INTERVAL YEAR TO MONTH.

Second, insert data into the candidates table:

INSERT INTO
  candidates (
    first_name,
    last_name,
    job_title,
    year_of_experience
  )
VALUES
  (
    'Camila',
    'Kramer',
    'SCM Manager',
    INTERVAL '10-2' YEAR TO MONTH
  );Code language: SQL (Structured Query Language) (sql)

In this statement, we inserted an interval literal of 10 years 2 months into the year_of_experience column.

INSERT INTO
  candidates (
    first_name,
    last_name,
    job_title,
    year_of_experience
  )
VALUES
  ('Keila', 'Doyle', 'SCM Staff', INTERVAL '9' MONTH);Code language: SQL (Structured Query Language) (sql)

In this statement, we inserted an interval literal 9 months into the year_of_experience column.

Third, query data from the INTERVAL YEAR TO MONTH column:

SELECT * FROM candidates; Code language: SQL (Structured Query Language) (sql)

Converting a number to an INTERVAL YEAR TO MONTH #

To convert a number to an INTERVAL YEAR TO MONTH, you use the numtoyminterval() function. For example:

SELECT numtoyminterval(37, 'MONTH') interval;Code language: JavaScript (javascript)

Output:

INTERVAL
--------
+03-01

In this example, we use the numtoyminterval function to convert 37 months to a YEAR TO MONTH interval. The result is an interval of 3 years 1 month (+03-01).

Calculating an INTERVAL YEAR TO MONTH between two dates #

In Oracle, when you subtract two dates or timestamps, you get a number of day (and fractions of a day if time is included. Oracle does not automatically convert the result to an interval.

To convert the result of two dates into an interval, you can use the months_between , trunc, and numtoyminterval() functions:

• months_between function returns the month between two dates.
• trunc function removes the decimal part and returns full months.
• numtoyminterval() function converts the number of months to an INTERVAL YEAR TO MONTH.

For example, the following statement returns an INTERVAL YEAR TO MONTH between 2025-05-11 and 2020-04-11:

SELECT
  NUMTOYMINTERVAL (
    TRUNC (
      MONTHS_BETWEEN (DATE '2025-05-11', DATE '2020-04-10')
    ),
    'MONTH'
  ) RESULT
FROM
  dual;Code language: JavaScript (javascript)

Output:

RESULT
------
+05-01

It returns an interval of 5 years and 1 month.

How it works:

• First, the months_between function returns 61.0322581 months.
• Second, the trunc function converts 61.0322581 to 61.
• Third, the numtoyminterval converts 61 months to an interval of 5 year 1 month.

Oracle INTERVAL DAY TO SECOND data type #

The INTERVAL DAY TO SECOND stores a period of time in terms of days, hours, minutes, and seconds.

The following shows the syntax of the INTERVAL DAY TO SECOND data type:

INTERVAL DAY [(day_precision)] TO SECOND [(fractional_seconds_precision)]Code language: SQL (Structured Query Language) (sql)

In this syntax:

• day_precision is the number of digits in the DAY field. It ranges from 0 to 9. By default, its value is set to 2.
• fractional_seconds_precision is the number of digits in the fractional part of the SECOND field. It ranges from 0 through 9. If you omit the fractional_seconds_precision, it defaults to 6.

Oracle INTERVAL DAY TO SECOND literals #

The literal form of INTERVAL DAY TO SECOND is as follows:

INTERVAL leading (leading_precision) TO trailing(fractional_seconds_precision)Code language: SQL (Structured Query Language) (sql)

The following table shows some examples of INTERVAL DAY TO SECOND literals:

Summary #

• Use the Oracle interval data types to store interval.
• Use the INTERVAL YEAR TO MONTH to store intervals in years and months.
• Use the INTERVAL DAY TO SECOND data type to store intervals in days, hours, minutes, and seconds.