How to recursively concatenate columns in SQLite query - sql

I have created a database which stores some simulations results in this way:
+--------------+--------+--------+-------------+--------------+
| SimulationID | TypeID | UserID | InputListID | OutputListID |
+--------------+--------+--------+-------------+--------------+
| 1 | 1 | 1 | 1 | 11 |
+--------------+--------+--------+-------------+--------------+
| 2 | 1 | 1 | 2 | 12 |
+--------------+--------+--------+-------------+--------------+
| 3 | 1 | 1 | 3 | 13 |
+--------------+--------+--------+-------------+--------------+
Where InputListID refers to other tables where group of variables are stored. Each simulation could have different number of parameters. If I simply use SELECT connecting the simulations with the variables I get the following table:
+--------------+--------------+---------------+---------------+
| SimulationID | VariableName | VariableValue | VariableUnits |
+--------------+--------------+---------------+---------------+
| 1 | Young Mod | 100 | GPa |
+--------------+--------------+---------------+---------------+
| 1 | Poisson | 0.3 | NULL |
+--------------+--------------+---------------+---------------+
| 2 | Young Mod | 101 | GPa |
+--------------+--------------+---------------+---------------+
| 2 | Poisson | 0.25 | NULL |
+--------------+--------------+---------------+---------------+
Is it possible to recursively concatenate columns to have something like this:
+--------------+-----------+---------+
| SimulationID | Young Mod | Poisson |
+--------------+-----------+---------+
| 1 | 100 | 0.3 |
+--------------+-----------+---------+
| 2 | 101 | 0.25 |
+--------------+-----------+---------+
Where the number of columns could change depends on the number of parameters and if units for example are wanted as well?
I am a beginner in SQL, so I apologize in advance if the question seems silly!

Related

How to use recursive query to add columns to a select?

So I have an accounts table in witch row may or may not have a parent account (0 means it doesn't have a parent):
+----+-----------+
| id | parent_id |
+----+-----------+
| 1 | 2 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 4 |
+----+-----------+
I was trying to add the top 3 parents for each row, so I would get something like this:
+----+-----------+----------+----------+----------+
| id | parent_id | parent_1 | parent_2 | parent_3 |
+----+-----------+----------+----------+----------+
| 1 | 2 | 2 | null | null |
| 2 | 0 | null | null | null |
| 3 | 1 | 2 | 1 | null |
| 4 | 3 | 2 | 1 | 3 |
| 5 | 4 | 2 | 1 | 3 |
+----+-----------+----------+----------+----------+
I figured I can do it with recursive queries, but I haven't managed to build a working query.
Any help would be appreciated.

SQL Server 2016 count similar rows as a column without duplicating query

I have a SQL query that returns data similar to this pseudo-table:
| Name | Id1 | Id2 | Guid |
|------+-----+-----+------|
| Joe | 1 | 1 | 1123 |
| Joe | 2 | 1 | 1123 |
| Joe | 3 | 1 | 1120 |
| Jeff | 1 | 1 | 1123 |
| Moe | 3 | 42 | 1120 |
I would like to display an additional column on the output, listing the total number of records that have matching GUIDs to a given row, like this:
| Name | Id1 | Id2 | Guid | # Matching |
+------+-----+-----+------+------------+
| Joe | 1 | 1 | 1123 | 3 |
| Joe | 2 | 1 | 1123 | 3 |
| Joe | 3 | 1 | 1120 | 2 |
| Jeff | 1 | 1 | 1123 | 3 |
| Moe | 3 | 42 | 1120 | 2 |
I was able to accomplish this by joining the query with itself, and doing a count. However, the query is rather large and takes awhile to complete, is there any way I can accomplish this without joining the query with itself?
You want a window function:
select t.*, count(*) over (partition by guid) as num_matching
from t;

How can I efficiently store large number sequences in a SQL db?

I want to store some number sequences in my database. So I:
+-----+---------+-----+
| idx | seq_id | x |
+-----+---------+-----+
| 1 | 1 | 1 |
| 2 | 1 | 1 |
| 3 | 1 | 2 |
| 4 | 1 | 3 |
| 5 | 1 | 5 |
| 6 | 1 | 7 |
| 1 | 2 | 1 |
| 2 | 2 | 2 |
| 3 | 2 | 4 |
| 4 | 2 | 8 |
| 5 | 2 | 16 |
| ... |
+-----+---------+-----+
but when I look at it, it feels like I'm storing more overhead with idx and seq_id than meaningful information.
In some sense I am, but I wouldn't find strange if the database engine optimized most of the repetition here. Is this the case for SQLite, MySQL, Postgre...?
And what can I make, perhaps in terms of table definition, to help the db optimize this storage pattern?

Selecting all rows in a master table and summing columns in multiple detail tables

I have a master table (Project List) along with several sub tables that are joined on one common field (RecNum). I need to get totals for all of the sub tables, by column and am not sure how to do it. This is a sample of the table design. There are more columns in each table (I need to pull * from "Project List") but I'm showing a sampling of the column names and values to get an idea of what to do.
Project List
| RecNum | Project Description |
| 6 | Sample description |
| 7 | Another sample |
WeekA
| RecNum | UserName | Day1Reg | Day1OT | Day2Reg | Day2OT | Day3Reg | Day3OT |
| 6 | JustMe | 1 | 2 | 3 | 4 | 5 | 6 |
| 6 | NotMe | 1 | 2 | 3 | 4 | 5 | 6 |
| 7 | JustMe | | | | | | |
| 7 | NotMe | | | | | | |
WeekB
| RecNum | UserName | Day1Reg | Day1OT | Day2Reg | Day2OT | Day3Reg | Day3OT |
| 6 | JustMe | 7 | 8 | 1 | 2 | 3 | 4 |
| 6 | NotMe | 7 | 8 | 1 | 2 | 3 | 4 |
| 7 | JustMe | | | | | | |
| 7 | NotMe | | | | | | |
So the first query should return the complete totals for both users, like this:
| RecNum | Project Description | sumReg | sumOT |
| 6 | Sample description | 40 | 52 |
| 7 | Another sample | 0 | 0 |
The second query should return the totals for just a specified user, (WHERE UserName = 'JustMe') like this:
| RecNum | Project Description | sumReg | sumOT |
| 6 | Sample description | 20 | 26 |
| 7 | Another sample | 0 | 0 |
Multiple parallel tables with the same structure is usually a sign of poor database design. The data should really be all in one table, with additional columns specifying the week.
You can, however, use union all to bring the data together. The following is an example of a query:
select pl.recNum, pl.ProjectDescription,
sum(Day1Reg + Day2Reg + Day3Reg) as reg,
sum(Day1OT + Day2OT + Day3OT) as ot
from ProjectList pl join
(select * from weekA union all
select * from weekB
) w
on pl.recNum = w.recNum
group by l.recNum, pl.ProjectDescription,;
In practice, you should use select * with union all. You should list the columns out explicitly. You can add appropraite where clauses or conditional aggregation to get the results you want in any particular case.

Ask about query in sql server

i have table like this:
| ID | id_number | a | b |
| 1 | 1 | 0 | 215 |
| 2 | 2 | 28 | 8952 |
| 3 | 3 | 10 | 2000 |
| 4 | 1 | 0 | 215 |
| 5 | 1 | 0 |10000 |
| 6 | 3 | 10 | 5000 |
| 7 | 2 | 3 |90933 |
I want to sum a*b where id_number is same, what the query to get all value for every id_number? for example the result is like this :
| ID | id_number | result |
| 1 | 1 | 0 |
| 2 | 2 | 523455 |
| 3 | 3 | 70000 |
This is a simple aggregation query:
select id_number, sum(a*b)
from t
group by id_number
I'm not sure what the first column is for.