If I use the below code:
SELECT
(player.id, player.firstname, player.lastname) AS player,
FROM
player
I get this result:
+----------------+
| player |
+----------------+
| (1,Bob,Smith) |
+----------------+
| (2,John,Smith) |
+----------------+
I like it!
But I wanna use player.* instead of indicating each field.
I tried with:
SELECT
(player.*) AS player,
FROM
player
but the result is not like before: there are columns like:
+----+-----------+----------+
| id | firstname | lastname |
+----+-----------+----------+
| 1 | Bob | Smith |
+----+-----------+----------+
| 2 | John | Smith |
+----+-----------+----------+
Why? Is there a way to get a tuple with all the columns using player.*?
Use the table reference:
select player
from player;
Related
I have two tables products and product_attributs. One Product can have one or many attributs and these are filled by a dynamic web form (name and value inputs) added by the user as needed. For example for a drill the user could decide to add two attributs : color=blue and power=100 watts. For another product it could be 3 or more different attribus and for another it could have no special attributs.
products
| id | name | identifier | identifier_type | active
| ----------|--------------|-------------|------------------|---
| 1 | Drill | AD44 | barcode | true
| 2 | Polisher | AP211C | barcode | true
| 3 | Jackhammer | AJ2133 | barcode | false
| 4 | Screwdriver | AS4778 | RFID | true
product_attributs
|id | name | value | product_id
|----------|--------------|-------------|----------
|1 | color | blue | 1
|2 | power | 100 watts | 1
|3 | size | 40 cm | 2
|4 | energy | electrical | 3
|4 | price | 35€ | 3
so attributs could be anything which are set dynamically by the user. My need is to generate a report on CSV which contain all products with their attributs. Without a good experience in SQL I generated the following basic request :
SELECT pr.name, pr.identifier_type, pr.identifier, pr.active, att.name, att.value
FROM products as pr
LEFT JOIN product_attributs att ON pr.id = att.product_id
as you know the result will contain for the same product as many rows as attributs it has and this is not ideal for reporting. The ideal would be this :
|name | identifier_type | identifier | active | name | value | name | value
|-----------|-----------------|------------|--------|--------|-------|------ |------
|Drill | barcode | AD44 | true | color | blue | power | 100 w
|Polisher | barcode | AP211C | true | size | 40 cm | null | null
|Jackhammer | barcode | AJ2133 | true | energy | elect | price | 35 €
|Screwdriver| barcode | AS4778 | true | null | null | null | null
here I only showed a max of two attributes per product but it could be more if needed. Well I did some research and came across the pivot with crosstab function on Postgres but the problem it requests static values but this does not match my need.
thanks lot for your help and sorry for duplicates if any.
Thanks Laurenz Albe for your help. array_agg solved my problem. Here is the query if someone may be interested in :
SELECT
pr.name, pr.description, pr.identifier_type, pr.identifier,
pr.internal_identifier, pr.active,
ARRAY_TO_STRING(ARRAY_AGG (oa.name || ' = ' || oa.value),', ') attributs
FROM
products pr
LEFT JOIN product_attributs oa ON pr.id = oa.product_id
GROUP BY
pr.name, pr.description, pr.identifier_type, pr.identifier,
pr.internal_identifier, pr.active
ORDER BY
pr.name;
I have a table "Listing" that looks like this:
| listing_id | amenities |
|------------|--------------------------------------------------|
| 5629709 | {"Air conditioning",Heating, Essentials,Shampoo} |
| 4156372 | {"Wireless Internet",Kitchen,"Pets allowed"} |
And another table "Amenity" like this:
| amenity_id | amenities |
|------------|--------------------------------------------------|
| 1 | Air conditioning |
| 2 | Kitchen |
| 3 | Heating |
Is there a way to join the two tables in a new one "Listing_Amenity" like this:
| listing_id | amenities |
|------------|-----------|
| 5629709 | 1 |
| 5629709 | 3 |
| 4156372 | 2 |
You could use unnest:
CREATE TABLE Listing_Amenity
AS
SELECT l.listing_id, a.amenity_id
FROM Listing l
, unnest(l.ammenities) sub(elem)
JOIN Amenity a
ON a.ammenities = sub.elem;
db<>fiddle demo
I have 2 column spark Scala DataFrame. The first is of one variable, the second one is an array of letters. What I am trying to do is find a way to code a tally (without using a for loop) of the variables in an array.
For example, this is what I have (I am sorry its not that neat, this is my first stack post). You have 5 computers, each person is represented by a letter. I want to find a way to find out how many computers a person (A,B,C,D,E) has used.
+-----------------+--------------+
| id | [person] |
+-----------------+--------------+
| Computer 1 | [A,B,C,D] |
| Computer 2 | [A,B] |
| Computer 3 | [A,B,E] |
| Computer 4 | [A,C,D] |
| Computer 5 | [A,B,C,D,E] |
+-----------------+--------------+
What I would like to code up or asking if anyone has a solution would be something like this:
+---------+-----------+
| Person | [Count] |
+---------+-----------+
| A | 5 |
| B | 4 |
| C | 3 |
| D | 3 |
| E | 2 |
+---------+-----------+
Somehow count the people who are in arrays within the dataframe.
There's a function called explode which will expand the arrays into one row for each item:
| id | person
+-----------------+------------------------+
| Computer 1| A |
| Computer 1| B |
| Computer 1| C |
| Computer 1| D |
....
+---+----+----+----+----+
Then you can group by the person and count. Something like:
val df2 = df.select(explode($"person").as("person"))
val result = df2.groupBy($"person").count
I have a column table like this in my table PostgreSQL database
| Product|
|--------|
| A10A |
| A13 |
| A12B |
and i want to order it by the first like this:
| Product|
|--------|
| A10A |
| A12B |
| A13 |
If i use the normal order by im not getting the exact same result that i want
Hello and warm greetings to you all,
I am having some challenges writing a complex query in posgresql. the fact is i'm having problem writing this particular query period, and your help is kindly needed. lets get to it.
here are my tables
[products_tb] [client_tb] [sales_tb]
+--------------+ +-------------+ +-------------+--------------+-----+
| product_name | | client_name | | client_name | product_name | qty |
+--------------+ +-------------+ +-------------+--------------+-----+
| shoe | | john | | john | shoe | 20 |
+--------------+ +-------------+ +-------------+--------------+-----+
| belt | | bob | | john | belt | 9 |
+--------------+ +-------------+ +-------------+--------------+-----+
| kim | | bob | shoe | 2 |
+-------------+ +-------------+--------------+-----+
| bob | belt | 98 |
+-------------+--------------+-----+
| kim | shoe | 46 |
+-------------+--------------+-----+
| kim | belt | 3 |
+-------------+--------------+-----+
[query output] # this output will be displayed using php and html
+----------+-------+------+-----+-----+
| products | Total | john | bob | kim |
+----------+-------+------+-----+-----+
| shoe | 68 | 20 | 2 | 46 |
+----------+-------+------+-----+-----+
| belt | 110 | 9 | 98 | 3 |
+----------+-------+------+-----+-----+
I am trying to write a query which will allow me to produce the table [query output]. Any help will be much appreciated.
Thank you very much.
A version without using cross_tab:
select p.product_name, sum(s.qty),
sum(CASE WHEN c.client_name='john' THEN s.qty END) as john,
sum(CASE WHEN c.client_name='bob' THEN s.qty END) as bob,
sum(CASE WHEN c.client_name='kim' THEN s.qty END) as kim
from products_tb AS p
JOIN sales_tb AS s ON p.product_name=s.product_name
JOIN clients_tb AS c ON c.client_name=s.client_name
GROUP BY p.product_name;
http://sqlfiddle.com/#!12/afc9a/10
Here's one way of doing it using standard SQL:
SELECT st.product_name AS products,
SUM(st.qty) AS Total,
(SELECT SUM(st_john.qty)
FROM sales_tb st_john
WHERE client_name = 'john' AND st_john.product_name = st.product_name) AS john,
(SELECT SUM(st_bob.qty)
FROM sales_tb st_bob
WHERE client_name = 'bob' AND st_bob.product_name = st.product_name) AS bob,
(SELECT SUM(st_kim.qty)
FROM sales_tb st_kim
WHERE client_name = 'kim' AND st_kim.product_name = st.product_name) AS kim
FROM sales_tb st
GROUP BY product_name
See SQL Fiddle Demo