Dear readers of our blog, we'd like to recommend you to visit the main page of our website, where you can learn about our product SQLS*Plus and its advantages.
 
SQLS*Plus - best SQL Server command line reporting and automation tool! SQLS*Plus is several orders of magnitude better than SQL Server sqlcmd and osql command line tools.
 

REQUEST COMPLIMENTARY SQLS*PLUS LICENCE

Enteros UpBeat offers a patented database performance management SaaS platform. It proactively identifies root causes of complex revenue-impacting database performance issues across a growing number of RDBMS, NoSQL, and deep/machine learning database platforms. We support Oracle, SQL Server, IBM DB2, MongoDB, Casandra, MySQL, Amazon Aurora, and other database systems.

PostgreSQL date_part function

31 August 2020

PostgreSQL date_part function

PostgreSQL date_part  function extracts parts from the date.

The syntax of the date_part function in PostgreSQL

date_part( 'unit', date )

Parameters and function arguments

  • date – Date, timestamp, time, or interval value from which part of the date is to be extracted.
  • Unit – Type of the unit of the interval measurement, such as day, month, minute, hour, etc. E. This may be one of the following:
unitExplanation
centuryUses the Gregorian calendar, where the first century begins with ‘0001-01-01 00:00:00 AD’.
dayday of the month (1 to 31)
decadeThe year is divided by 10
dowday per week (0=Sunday, 1=Monday, 2=Tuesday,… 6=Saturday)
doyday of the week in a year (1 = first day of the year, 365/366 = last day of the year, depending on whether it is a leap year)
epochNumber of seconds from ‘1970-01-01 00:00:00 UTC’ if the date value. The number of seconds in an interval, if the value is an interval.
hourhour (0 to 23)
isodowday of the week (1=Monday, 2=Tuesday, 3=Wednesday,… 7=Sunday)
isoyearISO 8601 (where the year begins on Monday of the week containing January 4)
microsecondsSeconds (and fractions of a second) multiplied by 1,000,000
millenniummillennium significance
millisecondsSeconds (and fractions of a second) multiplied by 1000
minuteminute (0 to 59)
monthmonth number for the month (from 1 to 12), if the date value. Number of months (from 0 to 11), if the value of the interval
quartera quarter (1 to 4)
secondseconds (and fractions of a second)
timezoneTime zone offset from UTC, expressed in seconds
timezone_hourTime zone offset from UTC
timezone_minuteMinute time zone offset from UTC
weekWeekly number of the year based on ISO 8601 (where the year starts on Monday of the week containing January 4)
the yearyear as 4 digits

 

The date_part function can be used in the following PostgreSQL versions

PostgreSQL 11, PostgreSQL 10, PostgreSQL 9.6, PostgreSQL 9.5, PostgreSQL 9.4, PostgreSQL 9.3, PostgreSQL 9.2, PostgreSQL 9.1, PostgreSQL 9.0, PostgreSQL 8.4.

 

Consider some examples of the date_part function to understand how to use the date_part function in PostgreSQL with date values.
For example:

SELECT date_part('day', date '2019-04-25');

--Result: 25

SELECT date_part('month', date '2019-04-23');

--Result: 4

SELECT date_part('year', date '2019-04-23');

--Result: 2019

Let’s see how to use the date_part function in PostgreSQL with timestamp values.
For example:

SELECT date_part('day', timestamp '2019-04-23 08:44:21');

--Result: 23

SELECT date_part('month', timestamp '2019-04-23 08:44:21');

--Result: 4

SELECT date_part('minute', timestamp '2019-04-23 08:44:21');

--Result: 44

SELECT date_part('hour', timestamp '2019-04-23 08:44:21');

--Result: 8

Let’s see how to use the date_part function in PostgreSQL with time values.
For example:

SELECT date_part('minute', time '08:44:21');

--Result: 44

SELECT date_part('milliseconds', time '08:44:21.7');

--Result: 21700

Let’s see how to use the date_part function in PostgreSQL with interval values.
For example:

SELECT date_part('day', interval '8 days 4 hours');

--Result: 8

SELECT date_part('hour', interval '8 days 4 hours');

--Result: 4

Date functions in PostgreSQL , Time functions in PostgreSQL

 
Tags: , , , ,

MORE NEWS

 

Preamble​​NoSql is not a replacement for SQL databases but is a valid alternative for many situations where standard SQL is not the best approach for...

Preamble​​MongoDB Conditional operators specify a condition to which the value of the document field shall correspond.Comparison Query Operators $eq...

5 Database management trends impacting database administrationIn the realm of database management systems, moreover half (52%) of your competitors feel...

The data type is defined as the type of data that any column or variable can store in MS SQL Server. What is the data type? When you create any table or...

Preamble​​MS SQL Server is a client-server architecture. MS SQL Server process starts with the client application sending a query.SQL Server accepts,...

First the basics: what is the master/slave?One database server (“master”) responds and can do anything. A lot of other database servers store copies of all...

Preamble​​Atom Hopper (based on Apache Abdera) for those who may not know is an open-source project sponsored by Rackspace. Today we will figure out how to...

Preamble​​MongoDB recently introduced its new aggregation structure. This structure provides a simpler solution for calculating aggregated values rather...

FlexibilityOne of the most advertised features of MongoDB is its flexibility.  Flexibility, however, is a double-edged sword. More flexibility means more...

Preamble​​SQLShell is a cross-platform command-line tool for SQL, similar to psql for PostgreSQL or MySQL command-line tool for MySQL.Why use it?If you...

Preamble​​Writing an application on top of the framework on top of the driver on top of the database is a bit like a game on the phone: you say “insert...

Preamble​​Oracle Coherence is a distributed cache that is functionally comparable with Memcached. In addition to the basic function of the API cache, it...

Preamble​​IBM pureXML, a proprietary XML database built on a relational mechanism (designed for puns) that offers both relational ( SQL / XML ) and...

  What is PostgreSQL array? In PostgreSQL we can define a column as an array of valid data types. The data type can be built-in, custom or enumerated....

Preamble​​If you are a Linux sysadmin or developer, there comes a time when you need to manage an Oracle database that can work in your environment.In this...

Preamble​​Starting with Microsoft SQL Server 2008, by default, the group of local administrators is no longer added to SQL Server administrators during the...