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POSTGRESQL DATEDIFF HOW TO

Using a string like the following will push the date or timestamp to the start of the month. It helps to use DATE_TRUNC on the dates you are using to standardize them if you don’t need to be uber-precise.You can then cast this as whatever you’d like, do additional calculations, etc. In the above example, this will yield 14. EXTRACT the number of months from the interval.Multiply the number of years by 12 to get the number of months counted by those years (seems obvious, but I am outlining all the steps in excruciating detail).EXTRACT the number of years from the interval.Example: In the travel table, there are three columns: id, departure, and arrival.

POSTGRESQL DATEDIFF HOW TO

This will return an interval that may look something like “1 year 2 months 3 days” How to Calculate the Difference Between Two Timestamps in PostgreSQL Database: PostgreSQL Operators: AGE () EXTRACT () EPOCH Problem: You have two columns of the type timestamp and you want to calculate the difference between them. PostgreSQL: DATEPART(day,date2 - date1) MySQL: DATEDIFF(date1,date2). Note that it is subtracting the second from the first, so you must have them in this order. These functions describe how to find the difference in days between two dates.

Use the AGE function to calculate the difference between the end date and start date.

EXTRACT(year FROM age(end_date,start_date))*12 + EXTRACT(month FROM age(end_date,start_date)) You can then EXTRACT the pieces of the interval needed to calculate months and use them in a simple equation. This may not seem like we’ve gotten very far in calculating the number of months between the two dates, but stick with me on this one. The age function calculates the difference between two dates and returns an interval. The best way I have found to get around this is to use the built in AGE function. In PostgreSQL, subtracting one date from another will yield a number of days that then takes a tremendously complex formula to manipulate into months. Often it is more helpful to show the date as a number of months rather than a number of days.

One of the most basic calculations on dates is to tell the time elapsed between two dates.