- Mastering PostgreSQL 10
- Hans Jürgen Sch?nig
- 160字
- 2021-06-30 19:04:01
Loading some sample data
To make this chapter a pleasant experience for you, I have compiled some sample data, which has been taken from the BP energy report: http://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy/downloads.html.
Here is the data structure that will be used:
test=# CREATE TABLE t_oil (
region text,
country text,
year int,
production int,
consumption int
);
CREATE TABLE
The test data can be downloaded from our website using curl directly:
test=# COPY t_oil FROM PROGRAM '
curl https://www.cybertec-postgresql.com/secret/oil_ext.txt ';
COPY 644
As in the previous chapter, you can download the file before importing it. On some operating systems, curl is not there by default or has not been installed, so downloading the file before might be an easier option for many people.
There is data for between 1965 and 2010, for 14 nations in two regions of the world:
test=# SELECT region, avg(production) FROM t_oil GROUP BY region; region | avg ---------------+----------------------- Middle East | 1992.6036866359447005 North America | 4541.3623188405797101 (2 rows)