The last in a series of Postgres posts, Pat Shaughnessy wrote based on he presentation at the Barcelona Ruby Conference. You can also watch the video recording of the presentation. The series was originally published in his personal blog, and we is
Recently, I have been working on a project related to PostgreSQL database, documenting the knowledge that I have learned in this process. About PostgreSQL database online already have too many relevant introduction, in order to blog the system or
9.11. Network address type functions and operatorsTable 9-31 shows the operators that can be used for CIDR and inet . Operators , >>, and >>= are used to compute subnet inclusions: They only consider the network portion of two addresses, ignoring
Pg_dump is a tool for backing up the PostgreSQL database. It can even make a full, consistent backup when the database is being used concurrently, without blocking access to the database by other users. The dump format generated by
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
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
First, the basic concept:
SQL functions can contain any number of queries, but the function only returns the result of the last query (which must be a select). In simple cases, returns the first row of the last query result. If the last query does
PostgreSQL tutorial (18): client commands (2), postgresql tutorial
Pg_dump is a tool used to back up PostgreSQL databases. It can even perform a full and consistent backup when the database is being used concurrently without blocking
I have a lazy idea. How should this good idea begin? Well, this is an appropriate little madness: Why not build our own MongoDB version directly on the basis of postgres? It sounds far-fetched, but it's simple and real.
When the NoSQL movement was
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