Postgresql. select SUM value from arrays - postgresql

Condition:
There are two tables with arrays.
Note food.integer and price.food_id specified array.
CREATE TABLE food (
id integer[] NOT NULL,
name character varying(255),
);
INSERT INTO food VALUES ('{1}', 'Apple');
INSERT INTO food VALUES ('{1,1}', 'Orange');
INSERT INTO food VALUES ('{1,2}', 'banana');
and
CREATE TABLE price (
id bigint NOT NULL,
food_id integer[],
value double precision DEFAULT 0
);
INSERT INTO price VALUES (44, '{1}', 500);
INSERT INTO price VALUES (55, '{1,1}', 100);
INSERT INTO price VALUES (66, '{1,2}', 200);
Need to get the sum value of all the products from table food.
Please help make a sql query.
ANSWER:
{1} - Apple - 800 (500+100+200)

What about this:
select
name,
sum(value)
from
(select unnest(id) as food_id, name from food) food_cte
join (select distinct id, unnest(food_id) as food_id, value from price) price_cte using (food_id)
group by
name
It is difficult to understand your question, but this query at least returns 800 for Apple.

try the following command,
SELECT F.ID,F.NAME,SUM(P.VALUE) FROM FOOD F,PRICE P WHERE F.ID=P.FOOT_ID;

Related

How to distinct on a table with a pair of opposite id values and get one id pair?

I want to eliminate from a table with two id columns (aID, bId) the opposite Id pairs.
For example the aId = 123abc and the bId = 345def. The opposite side is aId = 345def and bId = 123abc. Another bId = 678def is not the opposite side from aId ! That should be listed.
How to get only one of this pairs, which one is even.
CREATE TABLE distinct_pair_of_id (
"aId" VARCHAR,
"bId" VARCHAR
);
INSERT INTO distinct_pair_of_id ("aId", "bId")
VALUES
('123abc', '345def'),
('345def', '123abc'),
('123abc', '678def'),
('678def', '123abc'),
('345def', '986def'),
('345def', '765def')
;
You could use a LEAST/GREATEST trick here:
SELECT DISTINCT LEAST(aId, bId) AS aId,
GREATEST(aId, bId) AS bId
FROM distinct_pair_of_id;
This would also return records having only one value but no pair. If you instead want to return only records which do have a pair, we can aggregate:
SELECT LEAST(aId, bId) AS aId,
GREATEST(aId, bId) AS bId
FROM distinct_pair_of_id
GROUP BY 1, 2
HAVING COUNT(*) > 1;

Postgresql - select query with aggregated decisions column as json

I have table which contains specified columns:
id - bigint
decision - varchar(80)
type - varchar(258)
I want to make a select query which in result returns something like this(id, decisionsValues with counts as json, type):
id decisions type
1 {"firstDecisionsValue":countOfThisValue, "secondDecisionsValue": countOfThisValue} entryType
I heard that I can try play with json_agg but it does not allow COUNT method, tried to use json_agg with query:
SELECT ac.id,
json_agg(ac.decision),
ac.type
FROM myTable ac
GROUP BY ac.id, ac.type;
but ends with this(for entry with id 1 there are two occurences of firstDecisionsValue, one occurence of secondDecisionsValue):
id decisions type
1 {"firstDecisionsValue", "firstDecisionsValue", "secondDecisionsValue"} entryType
minimal reproducible example
CREATE TABLE myTable
(
id bigint,
decisions varchar(80),
type varchar(258)
);
INSERT INTO myTable
VALUES (1, 'firstDecisionsValue', 'myType');
INSERT INTO myTable
VALUES (1, 'firstDecisionsValue', 'myType');
INSERT INTO myTable
VALUES (1, 'secondDecisionsValue', 'myType');
Can you provide me any tips how to make it as expected?
1, {"fistDecisionsValue":2, "secondDecisionsValue":1}, entryType
You can try this
SELECT a.id, jsonb_object_agg(a.decisions, a.count), a.type
FROM
( SELECT id, type, decisions, count(*) AS count
FROM myTable
GROUP BY id, type, decisions
) AS a
GROUP BY a.id, a.type
see the result in dbfiddle.
First, you should calculate the count of id, type, decisions for each decisions after that, you should use jsonb_object_agg to create JSON.
Demo
with data as (
select
ac.id,
ac.type,
ac.decisions,
count(*)
from
myTable ac
group by
ac.id,
ac.type,
ac.decisions
)
select
d.id,
d.type,
json_object_agg(d.decisions, d.count)
from
data d
group by
d.id,
d.type

Finding rows that have the same value with Postgres

Not sure if the title is descriptive enough (sorry about the bad english), but my problem is that I need to find the rows that have the same value in all rows.
Possibly easier to understand what I actually mean with an example:
I have an table that's called Catalogue with the attributes motortype, motorpart and partnumber where motortype and motorpart are VARCHAR and partnumber are int.
Some partnumbers are used in all the motortypes, and it's those partnumbers that I am interested in finding.
I'm having a hard time seeing how to solve this, so any help would be greatly appreciated!
EDIT:
Sorry if the question was lackful or bad. I have updated with the table schema, some sample data and my desired results under:
CREATE TABLE Catalogue (
motortype VARCHAR,
motorpart VARCHAR,
partnumber int,
PRIMARY KEY (partnumber)
);
Sample data:
INSERT INTO Catalogue VALUES ('M1', 'Brakes', 1);
INSERT INTO Catalogue VALUES ('M2', 'Brakes', 1);
INSERT INTO Catalogue VALUES ('M3', 'Brakes', 1);
INSERT INTO Catalogue VALUES ('M1', 'Gasket', 2);
INSERT INTO Catalogue VALUES ('M2', 'Gasket', 2);
INSERT INTO Catalogue VALUES ('M3', 'Pedal', 3);
Desired result:
| motorpart | partnumber |
|-----------|------------|
| Brakes | 1 |
Hope this was better formulated!
If there are 3 different types you can use next query:
select motorpart
from Catalogue
group by motorpart
having count(distinct motortype) >= 3;
If you don't know the number:
select motorpart
from Catalogue
group by motorpart
having count(distinct motortype) = (select distinct motortype
from Catalogue);
Rextester here

Insert into table from select distinct query in postgresql

I have a table with 33 columns that has several duplicates so i am trying to remove all the duplicates this way because this select distinct query has the correct number of data.
CREATE TABLE students (
school char(2),sex char(1),age int,address char(1),famsize char(3),
Pstatus char(1),Medu int,Fedu int,Mjob varchar,Fjob varchar,reason varchar,
guardian varchar,traveltime int,studytime int,failures char(1),
schoolsup varchar,famsup varchar,paid varchar,activities varchar,
nursery varchar,higher varchar,internet varchar,romantic varchar,
famrel int,freetime int,goout int,Dalc int,Walc int,
health int,absences int,id serial primary key)
I want to insert all values from this select distinct query
with 8 columns into a different empty table.
SELECT DISTINCT ("school","sex","age","address","famsize","Pstatus","Medu","Fedu","Mjob","Fjob","reason","nursery","internet")
FROM students;
I want to insert all values from this select distinct query with 8 columns into a different empty table.
Use create table .. as select ... if you want to create the table
create table new_table
as
SELECT DISTINCT school, sex, age, address, famsize, "Pstatus", "Medu", "Fedu", "Mjob", "Fjob", reason, nursery, internet
FROM students;
Other wise just use an insert based on a select:
insert into empty_table (school, sex, age, address, famsize, "Pstatus", "Medu", "Fedu", "Mjob", "Fjob", reason, nursery, internet)
SELECT DISTINCT school, sex, age, address, famsize, "Pstatus", "Medu", "Fedu", "Mjob", "Fjob", reason, nursery, internet
FROM students;
Very important: do not put parentheses around the columns in the select list - that creates a single column with an anonymous record type.
insert into destinationTable(dC1, dC2, dC3, dC4, dC5, dC6, dC7, dC8)
select sC1, sC2, sC3, sC4, sC5, sC6, sC7, sC8
from sourceTable
You can join the tables to get the 33 columns.

How can I SUM distinct records in a Postgres database where there are duplicate records?

Imagine a table that looks like this:
The SQL to get this data was just SELECT *
The first column is "row_id" the second is "id" - which is the order ID and the third is "total" - which is the revenue.
I'm not sure why there are duplicate rows in the database, but when I do a SUM(total), it's including the second entry in the database, even though the order ID is the same, which is causing my numbers to be larger than if I select distinct(id), total - export to excel and then sum the values manually.
So my question is - how can I SUM on just the distinct order IDs so that I get the same revenue as if I exported to excel every distinct order ID row?
Thanks in advance!
Easy - just divide by the count:
select id, sum(total) / count(id)
from orders
group by id
See live demo.
Also handles any level of duplication, eg triplicates etc.
You can try something like this (with your example):
Table
create table test (
row_id int,
id int,
total decimal(15,2)
);
insert into test values
(6395, 1509, 112), (22986, 1509, 112),
(1393, 3284, 40.37), (24360, 3284, 40.37);
Query
with distinct_records as (
select distinct id, total from test
)
select a.id, b.actual_total, array_agg(a.row_id) as row_ids
from test a
inner join (select id, sum(total) as actual_total from distinct_records group by id) b
on a.id = b.id
group by a.id, b.actual_total
Result
| id | actual_total | row_ids |
|------|--------------|------------|
| 1509 | 112 | 6395,22986 |
| 3284 | 40.37 | 1393,24360 |
Explanation
We do not know what the reasons is for orders and totals to appear more than one time with different row_id. So using a common table expression (CTE) using the with ... phrase, we get the distinct id and total.
Under the CTE, we use this distinct data to do totaling. We join ID in the original table with the aggregation over distinct values. Then we comma-separate row_ids so that the information looks cleaner.
SQLFiddle example
http://sqlfiddle.com/#!15/72639/3
Create custom aggregate:
CREATE OR REPLACE FUNCTION sum_func (
double precision, pg_catalog.anyelement, double precision
)
RETURNS double precision AS
$body$
SELECT case when $3 is not null then COALESCE($1, 0) + $3 else $1 end
$body$
LANGUAGE 'sql';
CREATE AGGREGATE dist_sum (
pg_catalog."any",
double precision)
(
SFUNC = sum_func,
STYPE = float8
);
And then calc distinct sum like:
select dist_sum(distinct id, total)
from orders
SQLFiddle
You can use DISTINCT in your aggregate functions:
SELECT id, SUM(DISTINCT total) FROM orders GROUP BY id
Documentation here: https://www.postgresql.org/docs/9.6/static/sql-expressions.html#SYNTAX-AGGREGATES
If we can trust that the total for 1 order is actually 1 row. We could eliminate the duplicates in a sub-query by selecting the the MAX of the PK id column. An example:
CREATE TABLE test2 (id int, order_id int, total int);
insert into test2 values (1,1,50);
insert into test2 values (2,1,50);
insert into test2 values (5,1,50);
insert into test2 values (3,2,100);
insert into test2 values (4,2,100);
select order_id, sum(total)
from test2 t
join (
select max(id) as id
from test2
group by order_id) as sq
on t.id = sq.id
group by order_id
sql fiddle
In difficult cases:
select
id,
(
SELECT SUM(value::int4)
FROM jsonb_each_text(jsonb_object_agg(row_id, total))
) as total
from orders
group by id
I would suggest just use a sub-Query:
SELECT "a"."id", SUM("a"."total")
FROM (SELECT DISTINCT ON ("id") * FROM "Database"."Schema"."Table") AS "a"
GROUP BY "a"."id"
The Above will give you the total of each id
Use below if you want the full total of each duplicate removed:
SELECT SUM("a"."total")
FROM (SELECT DISTINCT ON ("id") * FROM "Database"."Schema"."Table") AS "a"
Using subselect (http://sqlfiddle.com/#!7/cef1c/51):
select sum(total) from (
select distinct id, total
from orders
)
Using CTE (http://sqlfiddle.com/#!7/cef1c/53):
with distinct_records as (
select distinct id, total from orders
)
select sum(total) from distinct_records;