I'm trying to fill a table with data to test a system.
I have two tables
User
+----+----------+
| id | name |
+----+----------+
| 1 | Majikaja |
| 2 | User 2 |
| 3 | Markus |
+----+----------+
Goal
+----+----------+---------+
| id | goal | user_id |
+----+----------+---------+
I want to insert into goal one record for every user only using their IDs (they have to exists) and some fixed or random value.
I was thinking in something like this:
INSERT INTO Goal (goal, user_id) values ('Fixed value', select u.id from user u)
So it will generate:
Goal
+----+-------------+---------+
| id | goal | user_id |
+----+-------------+---------+
| 1 | Fixed value | 1 |
| 2 | Fixed value | 2 |
| 3 | Fixed value | 3 |
+----+-------------+---------+
I could just write a simple PHP script to achieve it but I wonder if is it possible to do using raw SQL only.
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 of users that has a column called order that represents the order in they will be elected.
So, for example, the table might look like:
| id | name | order |
|-----|--------|-------|
| 1 | John | 2 |
| 2 | Mike | 0 |
| 3 | Lisa | 1 |
So, say that now Lisa gets destroyed, I would like that in the same transaction that I destroy Lisa, I am able to update the table so the order is still consistent, so the expected result would be:
| id | name | order |
|-----|--------|-------|
| 1 | John | 1 |
| 2 | Mike | 0 |
Or, if Mike were the one to be deleted, the expected result would be:
| id | name | order |
|-----|--------|-------|
| 1 | John | 1 |
| 3 | Lisa | 0 |
How can I do this in PostgreSQL?
If you are just deleting one row, one option uses a cte and the returning clause to then trigger an update
with del as (
delete from mytable where name = 'Lisa'
returning ord
)
update mytable
set ord = ord - 1
from del d
where mytable.ord > d.ord
As a more general approach, I would really recommend trying to renumber the whole table after every delete. This is inefficient, and can get tedious for multi-rows delete.
Instead, you could build a view on top of the table:
create view myview as
select id, name, row_number() over(order by ord) ord
from mytable
I suspect this question is already well-answered but perhaps due to limited SQL vocabulary I have not managed to find what I need. I have a database with many code:description mappings in a single 'parameter' table. I would like to define a query or procedure to return the descriptions for all (or an arbitrary list of) coded values in a given 'content' table with their descriptions from the parameter table. I don't want to alter the original data, I just want to display friendly results.
Is there a standard way to do this?
Can it be accomplished with SELECT or are other statements required?
Here is a sample query for a single coded field:
SELECT TOP (5)
newid() as id,
B.BRIDGE_STATUS,
P.SHORTDESC
FROM
BRIDGE B
LEFT JOIN PARAMTRS P ON P.TABLE_NAME = 'BRIDGE'
AND P.FIELD_NAME = 'BRIDGE_STATUS'
AND P.PARMVALUE = B.BRIDGE_STATUS
ORDER BY
id
I want to produce 'decoded' results like:
| id | BRIDGE_STATUS |
|--------------------------------------|------------ |
| BABCEC1E-5FE2-46FA-9763-000131F2F688 | Active |
| 758F5201-4742-43C6-8550-000571875265 | Active |
| 5E51634C-4DD9-4B0A-BBF5-00087DF71C8B | Active |
| 0A4EA521-DE70-4D04-93B8-000CD12B7F55 | Inactive |
| 815C6C66-8995-4893-9A1B-000F00F839A4 | Proposed |
Rather than original, coded data like:
| id | BRIDGE_STATUS |
|--------------------------------------|---------------|
| F50214D7-F726-4996-9C0C-00021BD681A4 | 3 |
| 4F173E40-54DC-495E-9B84-000B446F09C3 | 3 |
| F9C216CD-0453-434B-AFA0-000C39EFA0FB | 3 |
| 5D09554E-201D-4208-A786-000C537759A1 | 1 |
| F0BDB9A4-E796-4786-8781-000FC60E200C | 4 |
but for an arbitrary number of columns.
I have two tables in postgresql looks something like below. please help me with the query to insert into table 1uid column based on column name2.
table 1 table 2
|uid|name1| |uid|name2|table 1uid|
| 1 | a | | 1 | b | |
| 2 | b | | 2 | C | |
| 3 | c | | 3 | a | |
The keyword you need to look for is Update (which changes existing rows). Insert is for creating brand new rows.
But for your particular case, something along the lines of:
update table2 set table1uid = (select uid from table1 where table1.name1 = table2.name2)
I have a table that looks like
+-------+-----------+
| value | timestamp |
+-------+-----------+
and I'm trying to build a query that gives a result like
+-------+-----------+------------+------------------------+
| value | timestamp | MAX(value) | timestamp of max value |
+-------+-----------+------------+------------------------+
so that the result looks like
+---+----------+---+----------+
| 1 | 1.2.1001 | 3 | 1.1.1000 |
| 2 | 5.5.1021 | 3 | 1.1.1000 |
| 3 | 1.1.1000 | 3 | 1.1.1000 |
+---+----------+---+----------+
but I got stuck on joining the column with the corresponding timestamps.
Any hints or suggestions?
Thanks in advance!
For further information (if that helps):
In the real project the max-values are grouped by month and day (with group by clause, which works btw), but somehow I got stuck on joining the timestamps for max-values.
EDIT
Cross joins are a good idea, but I want to have them grouped by month e.g.:
+---+----------+---+----------+
| 1 | 1.1.1101 | 6 | 1.1.1300 |
| 2 | 2.6.1021 | 5 | 5.6.1000 |
| 3 | 1.1.1200 | 6 | 1.1.1300 |
| 4 | 1.1.1040 | 6 | 1.1.1300 |
| 5 | 5.6.1000 | 5 | 5.6.1000 |
| 6 | 1.1.1300 | 6 | 1.1.1300 |
+---+----------+---+----------+
EDIT 2
I've added a fiddle for some sample data and and example of the current query.
http://sqlfiddle.com/#!1/efa42/1
How to add the corresponding timestamp to the maximum?
Try a cross join with two sub queries, the first one selects all records, the second one gets one row that represents the time_stamp of the max value, <3;"1000-01-01"> for example.
SELECT col_value,col_timestamp,max_col_value, col_timestamp_of_max_value FROM table1
cross join
(
select max(col_value) max_col_value ,col_timestamp col_timestamp_of_max_value from table1
group by col_timestamp
order by max_col_value desc
limit 1
) A --One row that represents the time_stamp of the max value, ie: <3;"1000-01-01">
Use the window cause you use with pg
Select *, max( value ) over (), max( timestamp ) over() from table
That gives you the max values from all values in every row
http://www.postgresql.org/docs/9.1/static/tutorial-window.html