interval 1 day postgres

Recently the company requested to back up the database, so we looked up the comparative information. Don't say much nonsense, into the subject.Objective: To regularly back up the Postgres database under Ubuntu, and to pack and upload to the

PG processing time is very flexible, +-*/both have supportIt's useful to have a extract function in the meantime, let's take a look at a few examples: [code]postgres=# Select Extract (Epoch from ' 1970-01-01 ':: timestamp);Date_part-----------0(1

Get system Time function Select Now (); --2013-11-28 16:20:25.259715+08 Select Current_timestamp; --2013-11-28 16:20:38.815466+08 Select current_date; --2013-11-28 Select Current_time; --16:21:08.981171+08 Calculation

Commonly used time and date scripts in PostgreSQL tutorial, postgresql tutorial Obtain System Time Functions select now(); --2013-11-28 16:20:25.259715+08select current_timestamp; --2013-11-28 16:20:38.815466+08select current_date; --2013

1. Function Description:Date_trunc: Intercept a given time (timestamp,date) to get the initial time of the specified precision (time, day, month, year)2. General TimeDate_trunc (' Hour ', TIMESTAMP ' 2018-08-16 20:38:40 ')Result:2018-08-16

It's not surprising when those of us who use rails see things like 5.weeks.from_nowor3.days.ago + 2.hours. Also, PostgreSQL can do this by simply calling PostgreSQL built-in functions to achieve the same functionality.Current time/date/time stamp

Those of us who use Rails will not be surprised when they see 5. weeks. from_nowor3.days.ago + 2. hours. Similarly, PostgreSQL can also achieve the same functionality by simply calling the built-in functions of PostgreSQL. PostgreSQL deletes

PostgreSQL has a very useful built-in function, generate_series, which can be used to generate a series of filled data according to different rules.I. Syntax generate_series(start,stop) --int or bigintgenerate_series(start,stop,step)

Those of us who use Rails will not be surprised when they see 5. weeks. from_nowor3.days.ago + 2. hours. You can also use PostgreSQL. Those of us who use Rails will not be surprised when they see 5. weeks. from_nowor3.days.ago + 2. hours. You can

I. Type conversionPostgres type conversion: Usually: used for type conversion, timestamp to date is used moreSelect now (): DateSelect now (): varcharExample 1: varchar of a date is calculated as date.Select '2017-11-15 16:15:56. 2012 + 08':