Converting MySQL Resultset from Rows to Columns - sql

I have output from a select like this:
04:47:37> select * from attributes left outer join trailer_attributes on attributes.id = trailer_attributes.attribute_id;
+----+--------------+----------+-----------+------------+--------------+-----------------+
| id | name | datatype | list_page | trailer_id | attribute_id | attribute_value |
+----+--------------+----------+-----------+------------+--------------+-----------------+
| 1 | Make | text | 1 | 1 | 1 | Apple |
| 1 | Make | text | 1 | 2 | 1 | sdfg |
| 2 | Year | number | 1 | 1 | 2 | 2009 |
| 2 | Year | number | 1 | 2 | 2 | sdfg |
| 3 | Type | text | 0 | 1 | 3 | iPhone |
| 3 | Type | text | 0 | 2 | 3 | sdfg |
| 4 | Axles | text | 0 | 1 | 4 | asdf |
| 4 | Axles | text | 0 | 2 | 4 | sdfg |
| 7 | Size | text | 0 | 1 | 7 | asd1 |
| 7 | Size | text | 0 | 2 | 7 | sdfg |
| 8 | Frame | text | 0 | 1 | 8 | |
| 8 | Frame | text | 0 | 2 | 8 | sdfg |
| 9 | Height | text | 0 | 1 | 9 | |
| 9 | Height | text | 0 | 2 | 9 | sdfg |
| 10 | Dollies | text | 0 | 1 | 10 | |
| 10 | Dollies | text | 0 | 2 | 10 | sdfg |
| 11 | Tires/Wheels | text | 0 | 1 | 11 | |
| 11 | Tires/Wheels | text | 0 | 2 | 11 | sdfg |
| 12 | Condition | text | 1 | 1 | 12 | New |
| 12 | Condition | text | 1 | 2 | 12 | sdfg |
| 13 | Title | text | 0 | 1 | 13 | |
| 13 | Title | text | 0 | 2 | 13 | sdfg |
+----+--------------+----------+-----------+------------+--------------+-----------------+
I want to convert it to something more along the lines of:
id, Make, Year, Type, Axles, Size, Frame (etc)
1, Apple, 2009, iPhone, .....
2, sdfg, sdfg, sdfg, .....
Any suggestions?

Mmmm...EAVs. One of the many reasons to avoid EAVs (entity-attribute_value) is that they are harder to report and query against. However, if the attributes you want are known ahead of time, you can do something like:
Select id
, Min( Case When name = 'Make' Then attribute_value End ) As Make
, Min( Case When name = 'Year' Then attribute_value End ) As Year
, Min( Case When name = 'Type' Then attribute_value End ) As Type
, Min( Case When name = 'Axles' Then attribute_value End ) As Axles
, Min( Case When name = 'Size' Then attribute_value End ) As Size
, Min( Case When name = 'Frame' Then attribute_value End ) As Frame
, ...
From attributes
Where name In('Make','Year','Type','Axles','Size','Frame',....)
Group By id
Now, MySQL, does have a GROUP_CONCAT which will let you concatenate multiple values for the same attribute into a list if you allow that (e.g. if an entity can have multiple Make attributes).

This may not be an option for you, but ideally you should convert each attribute into a column of the main table. Relational databases are designed to handle attributes as columns, not rows. Therefore they perform much better when you use them like that, and the SQL becomes much simpler too.

Related

How to assign duplicate increment in SQL?

While going through SQL columns, if we find text match "NEW" in Calc column, update the incrementing a count starting with 1 in Results column.
It should look like this on the output:
The following uses an id column to resolve the order issue. Replace that with your corresponding expression. This also addresses the requirement to start the display sequence with 1 and also show 0 for the 'NEW' rows.
The SQL (updated):
SELECT logs.*
, CASE WHEN text = 'NEW' THEN 0
ELSE
COALESCE(SUM(CASE WHEN text = 'NEW' THEN 1 END) OVER (PARTITION BY xrank ORDER BY id)+1, 1)
END AS display
FROM logs
ORDER BY id
The result:
+----+-------+------+---------+
| id | xrank | text | display |
+----+-------+------+---------+
| 1 | 1 | A | 1 |
| 2 | 1 | B | 1 |
| 3 | 1 | C | 1 |
| 4 | 1 | NEW | 0 |
| 5 | 1 | D | 2 |
| 6 | 1 | Q | 2 |
| 7 | 1 | B | 2 |
| 8 | 1 | NEW | 0 |
| 9 | 1 | D | 3 |
| 10 | 1 | Z | 3 |
| 11 | 2 | A | 1 |
| 12 | 2 | B | 1 |
| 13 | 2 | C | 1 |
| 14 | 2 | NEW | 0 |
| 15 | 2 | D | 2 |
| 16 | 2 | Q | 2 |
| 17 | 2 | B | 2 |
| 18 | 2 | NEW | 0 |
| 19 | 2 | D | 3 |
| 20 | 2 | Z | 3 |
+----+-------+------+---------+
You need a column that specifies the ordering for the table. With that, just use a cumulative sum:
select t.*,
1 + sum(case when Calc = 'NEW' then 1 else 0 end) over (partition by Rank_Id order by Seq) as display
from t;

SQL - Partition restarted based on a column value

I need to create a new column that restarts at every 0 value of Column Repeated Call of each Customer_ID:
+-------------+---------+----------------------+---------------+
| Customer_ID | Call_ID | Days Since Last Call | Repeated Call |
+-------------+---------+----------------------+---------------+
| 1 | 1 | Null | 0 |
| 1 | 2 | 45 | 0 |
| 1 | 3 | 0 | 1 |
| 1 | 4 | 0 | 1 |
| 1 | 5 | 0 | 1 |
| 1 | 6 | 48 | 0 |
| 1 | 7 | 1 | 1 |
| 2 | 8 | Null | 0 |
| 2 | 9 | 1 | 1 |
+-------------+---------+----------------------+---------------+
In to something like this:
+-------------+---------+----------------------+---------------+-------------+
| Customer_ID | Call_ID | Days Since Last Call | Repeated Call | Order_Group |
+-------------+---------+----------------------+---------------+-------------+
| 1 | 1 | Null | 0 | 1 |
| 1 | 2 | 45 | 0 | 2 |
| 1 | 3 | 0 | 1 | 2 |
| 1 | 4 | 0 | 1 | 2 |
| 1 | 5 | 0 | 1 | 2 |
| 1 | 6 | 48 | 0 | 3 |
| 1 | 7 | 1 | 1 | 3 |
| 2 | 8 | Null | 0 | 1 |
| 2 | 9 | 1 | 1 | 1 |
+-------------+---------+----------------------+---------------+-------------+
Appreciate your suggestion, thanks!
You can use SUM() window function:
select t.*,
sum(case when Repeated_Call = 0 then 1 else 0 end)
over (partition by Customer_ID order by Call_Id) Order_Group
from tablename t
See the demo (for MySql but it is standard SQL).
Results:
| Customer_ID | Call_ID | Days Since Last Call | Repeated_Call | Order_Group |
| ----------- | ------- | -------------------- | ------------- | ----------- |
| 1 | 1 | | 0 | 1 |
| 1 | 2 | 45 | 0 | 2 |
| 1 | 3 | 0 | 1 | 2 |
| 1 | 4 | 0 | 1 | 2 |
| 1 | 5 | 0 | 1 | 2 |
| 1 | 6 | 48 | 0 | 3 |
| 1 | 7 | 1 | 1 | 3 |
| 2 | 8 | | 0 | 1 |
| 2 | 9 | 1 | 1 | 1 |
You can calculation every 0 value in column Repeated Call (for each customer) using window analytic function COUNT with ROWS UNBOUNDED PRECEDING:
SELECT *,
COUNT(CASE WHEN Repeated Call=0 THEN 1 ELSE NULL END )OVER(PARTITION BY Customer_ID
ORDER BY Call_ID ROWS UNBOUNDED PRECEDING)Order_Gr FROM Table

SQL order by but repeat crescent numbers

I'm using SQL Server 2014 and i'm having a trouble with a query.
I have this scenario bellow:
| Number | Series | Name |
|--------|--------|---------|
| 9 | 1 | Name 1 |
| 5 | 3 | Name 2 |
| 8 | 2 | Name 3 |
| 7 | 3 | Name 4 |
| 0 | 1 | Name 5 |
| 1 | 2 | Name 6 |
| 9 | 2 | Name 7 |
| 3 | 3 | Name 8 |
| 4 | 1 | Name 9 |
| 0 | 1 | Name 10 |
and I need to get it ordered by series column like this:
| Number | Series | Name |
|--------|--------|---------|
| 9 | 1 | Name 1 |
| 8 | 2 | Name 3 |
| 5 | 3 | Name 2 |
| 7 | 1 | Name 5 |
| 1 | 2 | Name 6 |
| 0 | 3 | Name 4 |
| 4 | 1 | Name 9 |
| 9 | 2 | Name 7 |
| 3 | 3 | Name 8 |
| 0 | 1 | Name 10 |
Actually is more a sequency in "series" column than an ordenation.
1,2,3 again 1,2,3...
Somebody could help me?
You can do this using the ANSI standard function row_number():
select number, series, name
from (select t.*, row_number() over (partition by series order by number) as seqnum
from t
) t
order by seqnum, series;
This assigns "1" to the first record for each series, "2" to the second, and so on. The outer order by then puts all the "1"s together, all the "2" together. This has the effect of interleaving the values of the series.

SQL - only display rows that have the max value

I have this table that is already sorted but I want it to only display the maximum values... so instead of this table:
+------+-------+
| id | value |
+------+-------+
| 1 | 3 |
| 5 | 3 |
| 4 | 3 |
| 9 | 2 |
| 8 | 2 |
| 3 | 2 |
| 2 | 1 |
| 6 | 1 |
| 7 | 1 |
+------+-------+
I want this:
+------+-------+
| id | value |
+------+-------+
| 1 | 3 |
| 5 | 3 |
| 4 | 3 |
+------+-------+
I'm using SQLite. thanks for any help.
You can do this using a subquery. Here is one way:
select t.*
from t
where t.value = (select max(value) from t);

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.