Having two tables (table1, table2) with the same column names (generation, parent), the desired output would be the combination of all columns of both tables. Thereby the rows of table2 should join table1 so that the rows of table2 are matching those of table1 on generation column. The parent number should be ordered ascending for the entries in table1 as well as in table2. The number of rows of the query results should be equal of those of table1.
Given the following tables
table1:
| generation | parent |
|:----------:|:------:|
| 0 | 1 |
| 0 | 2 |
| 0 | 3 |
| 1 | 3 |
| 1 | 2 |
| 1 | 1 |
| 2 | 2 |
| 2 | 1 |
| 2 | 3 |
table2:
| generation | parent |
|:----------:|:------:|
| 1 | 3 |
| 1 | 1 |
| 1 | 3 |
| 2 | 1 |
| 2 | 2 |
| 2 | 3 |
The following queries are thought for creating and populating two sample tables as shown above:
create table table1(generation integer, parent integer);
insert into table1 (generation, parent) values(0,1),(0,2),(0,3),(1,3),(1,2),(1,1),(2,2),(2,1),(2,3);
create table table2(generation integer, parent integer);
insert into table2 (generation, parent) values(1,3),(1,1),(1,3),(2,1),(2,2),(2,3);
the imagined query should lead to the following desired result:
| table1_generation | table1_parent | table2_generation | table2_parent |
|:-----------------:|:-------------:|:-----------------:|:-------------:|
| 0 | 1 | | |
| 0 | 2 | | |
| 0 | 3 | | |
| 1 | 1 | 1 | 1 |
| 1 | 2 | 1 | 3 |
| 1 | 3 | 1 | 3 |
| 2 | 1 | 2 | 1 |
| 2 | 2 | 2 | 2 |
| 2 | 3 | 2 | 3 |
Current query looks as follows:
with
p as (
select
generation,
parent
from
table1
order by
generation,
parent
), o as(
select
generation,
parent
from
table2
order by
generation,
parent
)
select
p.generation as table1_generation,
p.parent as table1_parent,
o.generation as table2_generation,
o.parent as table2_parent
from
p
left join o on
o.generation=p.generation;
Which leads to the following result:
| table1_generation | table1_parent | table2_generation | table2_parent |
|:-----------------:|:-------------:|:-----------------:|:-------------:|
| 0 | 1 | | |
| 0 | 2 | | |
| 0 | 3 | | |
| 1 | 1 | 1 | 1 |
| 1 | 1 | 1 | 3 |
| 1 | 1 | 1 | 3 |
| 1 | 2 | 1 | 1 |
| 1 | 2 | 1 | 3 |
| 1 | 2 | 1 | 3 |
| 1 | 3 | 1 | 1 |
| 1 | 3 | 1 | 3 |
| 1 | 3 | 1 | 3 |
| 2 | 1 | 2 | 1 |
| 2 | 1 | 2 | 2 |
| 2 | 1 | 2 | 3 |
| 2 | 2 | 2 | 1 |
| 2 | 2 | 2 | 2 |
| 2 | 2 | 2 | 3 |
| 2 | 3 | 2 | 1 |
| 2 | 3 | 2 | 2 |
| 2 | 3 | 2 | 3 |
This link led to the conclusion, that any join command might not what is necessary here ... But union does only append rows... so for me it is absolutely unclear, how the desired result can be achieved o.O
Any help is highly appreciated. Thanks in advance!
The main misunderstanding on this question arose from the fact that you mentioned join, which is a very precisely mathematically defined concept based on the Cartesian product and can be applied to any two sets. So the current output is clear.
But as you wrote in the title, you want to put two tables side by side. You take advantage of the fact that they have the same number of rows (triples).
This select returns the output you want.
I made artificial join columns, row_number() OVER (order by generation, parent) as rnum, and moved the second table using the addition of three. I hope this helps you:
with
p as (
select
row_number() OVER (order by generation, parent) as rnum,
generation,
parent
from
table1
order by
generation,
parent
), o as(
select
row_number() OVER (order by generation, parent) as rnum,
generation,
parent
from
table2
order by
generation,
parent
)
select
p.generation as table1_generation,
p.parent as table1_parent,
o.generation as table2_generation,
o.parent as table2_parent
from
p
left join o on
o.rnum+3=p.rnum
order by 1,2,3,4;
Output:
table1_generation
table1_parent
table2_generation
table2_parent
0
1
(null)
(null)
0
2
(null)
(null)
0
3
(null)
(null)
1
1
1
1
1
2
1
3
1
3
1
3
2
1
2
1
2
2
2
2
2
3
2
3
I want to create a function that finds the the number of pno's with the sid (staff id) that have worked on it.
So for example if I wanted to find the sid's corresponding to pno = 1
select sid_worked_on(1)
count
-------
2
I would have 2 as sid 0 and 1 have worked on it.
This is the joined table from 3 different tables.
pno | a_sid | b_sid | c_sid
-----+--------+--------+--------
1 | 0 | 0 | 0
4 | 4 | 4 | 6
5 | 4 | 4 | 5
2 | 0 | 0 | 0
1 | 0 | 1 | 0
7 | 5 | 4 | 4
7 | 5 | 5 | 4
5 | 4 | 4 | 4
4 | 4 | 5 | 6
7 | 5 | 4 | 1
7 | 5 | 5 | 1
6 | 5 | 4 | 5
My only way of thinking how to do it would be to "flatten" the table into one column since there is no need for multiple columns and do distinct sid, but I haven't learnt how to do that yet.
pno | sid
-----+--------
1 | 0 |
4 | 4 |
5 | 4 |
2 | 0 |
1 | 0 |
7 | 5 |
7 | 5 |
5 | 4 |
4 | 4 |
7 | 5 |
7 | 5 |
6 | 5 |
--where the new table starts
1 | 0 |
4 | 4 |
5 | 4 |
2 | 0 |
1 | 1 |
7 | 4 |
...
...
I also thought to create a table and going through each value, so
create table
for each row where pno = 1
check if a_sid in table
if not then add a_sid to table
check if b_sid in table
if not then add b_sid to table
check if c_sid in table
if not then add c_sid to table
Would there be a better way of doing this?
Use UNION
SELECT pno, a_sid from table
UNION
SELECT pno, b_sid from table
UNION
SELECT pno, c_sid from table
Depending on whether you want duplicated entries of the same pno with the same column on the right side, you can use UNION ALL instead of UNION.
You can create a view with this query.
I need to select first 2 lines where the store_name is different than one given for a given product
id | store_name | prod_name
----+------------+------
1 | 1 | A
2 | 1 | B
3 | 1 | C
4 | 1 | A
5 | 2 | E
6 | 2 | A
7 | 3 | G
8 | 2 | A
9 | 1 | A
10 | 3 | A
(10 rows)
result should be store_name <> 3 AND prod_name ='A'
id | store_name | prod_name
----+------------+------
1 | 1 | A
4 | 1 | A
6 | 2 | A
8 | 2 | A
Use the row_number() window function to accomplish this.
Query #1
with first_two as (
select *,
row_number() over (partition by store_name
order by id) as rn
from store_product
where store_name <> 3
and prod_name = 'A'
)
select id, store_name, prod_name
from first_two
where rn <= 2;
| id | store_name | prod_name |
| --- | ---------- | --------- |
| 1 | 1 | A |
| 4 | 1 | A |
| 6 | 2 | A |
| 8 | 2 | A |
View on DB Fiddle
I'm running postgres 9.4
I'm essentially updating an existing unorganized structure to a folder based organization. Im auto-assigning an order number to each item for user reordering, but doing an initial setting of all of these values with a 1 time use update statement. However, It seems like SET is taking my subquery's from clause and not recreating it for each successive row that it sets.
Here's my query example:
UPDATE folder_items
SET order_number =
(SELECT COALESCE(MAX(folder_items_2.order_number), 0) + 1
FROM folder_items AS folder_items_2
WHERE folder_items.parent_folder_id = folder_items_2.parent_folder_id
AND folder_items.folder_set_id = folder_items_2.folder_set_id
AND folder_items.id != folder_items_2.id);
With my initial table:
| folder_id | folder_set_id | order_number
row 1 | 1 | 1 | null
row 2 | 2 | 1 | null
row 3 | 3 | 2 | null
row 4 | 4 | 2 | null
row 5 | 5 | 2 | null
row 6 | 6 | 3 | null
when I run my query I get something like
| folder_id | folder_set_id | order_number
row 1 | 1 | 1 | 1
row 2 | 2 | 1 | 1
row 3 | 3 | 2 | 1
row 4 | 4 | 2 | 1
row 5 | 5 | 2 | 1
row 6 | 6 | 3 | 1
However, I want results that look like this:
| folder_id | folder_set_id | order_number
row 1 | 1 | 1 | 1
row 2 | 2 | 1 | 2
row 3 | 3 | 2 | 1
row 4 | 4 | 2 | 2
row 5 | 5 | 2 | 3
row 6 | 6 | 3 | 1
Is there a way to get these desired results? Is the best way to do some sort of window function that counts how many in the same folder_set_id are underneath each row?
Use ROW_NUMBER to calculate the ORDER_ID, then update the table.
with new_order as (
SELECT "folder_id",
row_number() over ( partition by "folder_set_id"
order by "folder_id") as rn
FROM Table1
)
UPDATE Table1 AS t
SET "order_number" = n.rn
FROM new_order AS n
WHERE t."folder_id" = n."folder_id";
SQL DEMO
OUTPUT
| row_id | folder_id | folder_set_id | order_number |
|--------|-----------|---------------|--------------|
| row 1 | 1 | 1 | 1 |
| row 2 | 2 | 1 | 2 |
| row 3 | 3 | 2 | 1 |
| row 4 | 4 | 2 | 2 |
| row 5 | 5 | 2 | 3 |
| row 6 | 6 | 3 | 1 |
I have two table table:
I. Table 1 like this:
------------------------------------------
codeid | pos | neg | category
-----------------------------------------
1 | 10 | 3 | begin2016
1 | 3 | 5 | justhere
3 | 7 | 7 | justthere
4 | 1 | 1 | else
4 | 12 | 0 | begin2015
4 | 5 | 12 | begin2013
1 | 2 | 50 | now
2 | 5 | 33 | now
5 | 33 | 0 | Begin2011
5 | 11 | 7 | begin2000
II. Table 2 like this:
------------------------------------------
codeid | codedesc | codegroupid
-----------------------------------------
1 | road runner | 1
2 | bike warrior | 2
3 | lazy driver | 4
4 | clever runner | 1
5 | worker | 3
6 | smarty | 1
7 | sweety | 3
8 | sweeper | 1
I want to have one result like this having two (or more) conditions:
sum pos and neg where codegroupid IN('1', '2', '3')
BUt do not sum pos and neg if category like 'begin%'
So the result will like this:
------------------------------------------
codeid | codedesc | sumpos | sumneg
-----------------------------------------
1 | roadrunner | 5 | 55 => (sumpos = 3+2, because 10 have category like 'begin%' so doesn't sum)
2 | bike warrior | 5 | 33
4 | clever runner | 1 | 1
5 | worker | 0 | 0 => (sumpos=sumneg=0) becase codeid 5 category ilike 'begin%'
Group by codeid, codedesc;
Sumpos is sum(pos) where category NOT ILIKE 'begin%', BUT IF category ILKIE 'begin%' make all pos values become zero (0);
Sumpos is sum(neg) where category NOT ILIKE 'begin%', BUT IF category ILKIE 'begin%' make all neg values become zero;
Any ideas how to do it?
Try:
SELECT
b.codeid,
b.codedesc,
sum(CASE WHEN category LIKE 'begin%' THEN 0 ELSE a.pos END) AS sumpos,
sum(CASE WHEN category LIKE 'begin%' THEN 0 ELSE a.neg END) AS sumneg
FROM
table1 AS a
JOIN
table2 AS b ON a.codeid = b.codeid
WHERE b.codegroupid IN (1, 2, 3)
GROUP BY
b.codeid,
b.codedesc;