Generate rows and insert into a table - sql

Question

I've following table
CREATE TABLE public.af01
(
id integer NOT NULL DEFAULT nextval('af01_id_seq'::regclass),
idate timestamp without time zone,
region text,
city text,
vtype text,
vmake text,
vmodel text,
vregno text,
intime time without time zone,
otime time without time zone,
vstatus boolean,
remarks text,
vowner text
);
I need to add data into it.This data should be for 1 Year, (data from 01-01-2016 to 31-12-2016). in a single date can have 5 entries,
Region column must have 3 values (Central,Western,Eastern),
City column must have 3 values(City1,City2,City3)
vtype column is the Vehicle type for example Heavy,light,Other.
vmake column is the manufacturer Audi,Nissan,Toyota,Hyundai,GMC etc.
vregno this column is for vechicle registration number and it should be unique (Ex.reg no CFB 4587).
intime any random time in day('10:15 AM').
otime this column should be intime+ 5 or 10 or 15 or 20.vstatus column should have True or false.
I've ended up with this select query to generate date rows
select '2013-01-01'::date + (n || ' days')::interval days
from generate_series(0, 365) n;
and
to generate first part of the Vehicle regno.
SELECT substring(string_agg (substr('ABCDEFGHIJKLMNOPQRSTUVWXYZ', ceil (random() * 62)::integer, 1), ''),1,3) t
FROM generate_series(0,45);
expected output;
id idate region city vtype vmake vmodel vregno intime otime vstatus remarks vowner
-- ---------- ------- ----- -------------- ------ ------ -------- ------------------- ------------------- ------- ------- ------
1 2016-01-01 Central City1 Heavy Vechicle Nissan Model1 NGV 4578 12:15:00 12:30:00 1 NULL Tom
2 2016-01-01 Western City1 Light Audi S3 BFR 4587 10:20:00 10:40:00 1 NULL Jerry

Answer 1

r_dates relation is just simple way to generate dates in ranges.
other_const and max_const are arrays and its length respectively for population. region[(random() * region_max)::int2 + 1] - choose element in array by random
INSERT INTO af01 (idate, region, city, vtype, vmake, vregno, intime, otime, vstatus)
SELECT cd, r, c, v, vm, rn, intime, intime + len as otime, status
FROM (
WITH r_dates AS (
SELECT generate_series('2013-01-01'::date, '2013-12-31'::date, '1 day'::interval) as cd
), other_const AS (
SELECT '{Central,Western,Eastern}'::text[] AS region,
'{City1,City2,City3}'::text[] as cities,
'{Heavy,light,Other}'::text[] as vehicles,
'{Audi,Nissan,Toyota,Hyundai,GMC}'::text[] as vmakes,
'{5,10,15,20}'::int4[] AS lengths,
'ABCDEFGHIJKLMNOPQRSTUVWXYZ'::text AS regnosrc
), max_const AS (
SELECT array_upper(region, 1) - 1 AS region_max,
array_upper(cities, 1) - 1 AS cities_max,
array_upper(vehicles, 1) - 1 AS vehicles_max,
array_upper(vmakes, 1) - 1 AS vmakes_max,
array_upper(lengths, 1) - 1 AS lengths_max
FROM other_const
)
SELECT cd,
region[(random() * region_max)::int2 + 1] AS r,
cities[(random() * cities_max)::int2 + 1] AS c,
vehicles[(random() * vehicles_max)::int2 + 1] AS v,
vmakes[(random() * vmakes_max)::int2 + 1] AS vm,
(
SELECT string_agg(s, '')
FROM (
SELECT substr(regnosrc, (random() * (length(regnosrc) - 1))::int4 + 1, 1) AS s
FROM generate_series(1, 3)
) AS a
)
|| lpad(((random() * 9999)::int8)::text, 4, '0') AS rn,
'00:00:00'::time + (((random() * 24 * 60)::int8)::text || 'min')::interval AS intime,
((lengths[(random() * lengths_max)::int2 + 1])::text || 'min')::interval AS len,
random() > 0.5 AS status
FROM r_dates, other_const, max_const, generate_series(1, 5)
) AS A