Is there a name for this representation of data? - data-structures

Suppose you have data for which a normalized view would be something like
ID First Name Last Name Height
-- ---------- --------- ------
1 Ann Jones 63
2 John Smith 72
But the data comes to us in this representation:
ID Type Value
-- ---- -----
1 'FirstName' Ann
1 'LastName' Jones
1 'Height' 63
2 'FirstName' John
2 'LastName' Smith
2 'Height' 72
It's sort of a normalized table turned sideways, or an "unpivoted" table.
My question is: is there a NAME for this kind of representation -- these 'ID, Type, Value' triples? (In reality the Type is an integer and maps to a type table, but I made it a string to make it clearer what it represented.)

I suppose this could be considered as close to the EAV (Entity-Attribute-Value) Model
Except you only have the two following tables :
Entity
Value
And no Attribute table.

Related

How to categorize data in a ORACLE table based on a primary key?

I have a table TRAVEL with column TRIP_ID as primary key.
SOURCE DATA
TRIP_ID PERSON_NAME DESTINATION SOURCE TRANSACTION_ID TRIP_COUNT
100 Mike London Zurich 1000B112 1
101 Mike Paris Capetown 1000B112 1
102 Mike Moscow Madrid 1000B112 1
103 John Delhi Moscow 1100A110 1
104 John Toronto Zurich 1100A110 1
105 Mary Chennai Madrid 1100A111 1
106 Mary Berlin Zurich 1100A111 1
EXPECTED RESULTS:
when I do select * from TRAVEL where TRANSACTION_ID = 1100A111 it returns below two rows as below .
so I want my data to be categorized based on the transaction_ID on a run time.I dont want to hardcode the value for transaction-ID each time as above but i want to group it in such a way that it should fetch me the above expected results.I mean it should return all the data which are corresponding to the TransactionID in the table and it should not sum up the TRIP COUNT.It should return me the rows as below in my table.I am ok to create view .Please suggest
TRIP_ID PERSON_NAME DESTINATION SOURCE TRANSACTION_ID TRIP_COUNT
105 Mary Chennai Madrid 1100A111 1
106 Mary Berlin Zurich 1100A111 1
Can someone suggest a query in ORACLE to handle this ? I donot want to hardcode transaction ID
Regards
Sameer

Oracle Query Prevent Displayed Duplicate Record

Let's say i have a table structure like this :
ID | Name | SCHOOLNAME | CODESCHOOL
1 DARK Kindergarten 123 1
2 DARK Kindergarten 111 1
3 Knight NY University 3
4 Knight LA Senior HS 2
5 JOHN HARVARD 3
so, how to diplay all of the data above into like this :
ID | Name | SCHOOLNAME | CODESCHOOL
1 DARK Kindergarten 123 1
3 Knight NY University 3
5 JOHN HARVARD 3
my purpose is want to display data with the max of codeschool, but when i tried with my query below :
SELECT NAME, SCHOOLNAME, MAX(CODESCHOOL) FROM TABLE GROUP BY NAME, SCHOOLNAME
but the result is just like this :
ID | Name | SCHOOLNAME | CODESCHOOL
1 DARK Kindergarten 123 1
2 DARK Kindergarten 111 1
3 Knight NY University 3
4 Knight LA Senior HS 2
5 JOHN HARVARD 3
maybe it caused by the GROUP BY SCHOOLNAME, when i tried to not select SCHOOLNAME, the data displayed just like what i expected, but i need the SCHOOLNAME field for search condition in my query
hope you guys can help me out of this problem
any help will be appreciated
thanks
Using some wacky joins you can get a functional get max rows per category query.
What you essentially need to do is to join the table to itself and make sure that the joined values only contain the top values for the CODESCHOOL column.
I've also added a :schoolname parameter because you wanted to search by schoolname
Example:
SELECT
A.*
FROM
TABLE1 A
LEFT OUTER JOIN TABLE1 B ON B.NAME = A.NAME
AND B.CODESCHOOL < A.CODESCHOOL
WHERE
B.CODESCHOOL IS NULL AND
(
(A.SCHOOLNAME = :SCHOOLNAME AND :SCHOOLNAME IS NOT NULL) OR
(:SCHOOLNAME IS NULL)
);
this should create this output, note that dark has 2 outputs because it has 2 rows with the same code school which is the max in the dark "category"/name.
ID|NAME |SCHOOLNAME |CODESCHOOL
--| -----|----------------|----------
4|Knight|LA Senior HS | 2
5|JOHN |HARVARD | 3
2|DARK |Kindergarten 111| 1
1|DARK |Kindergarten 123| 1
It's not the most effective query but it should be more than good enough as a starting point.
Sidenote: I've been blatantly stealing this logic for a while from https://www.xaprb.com/blog/2007/03/14/how-to-find-the-max-row-per-group-in-sql-without-subqueries/
I am using an analytical window function ROW_NUMBER().
This will group (or partition) by NAME then select the top 1 CODESCHOOL in DESC order.
Select NAME,
SCHOOLNAME,
CODESCHOOL
From (
Select NAME,
SCHOOLNAME,
CODESCHOOL,
ROW_NUMBER() OVER (PARTITION BY NAME ORDER BY CODESCHOOL DESC) as rn
from myTable)
Where rn = 1;

Oracle LRS: Linear Referencing in Oracle

Does anybody know how to do Linear Referencing in Oracle?
I have a table with my route geometries, like
id routename geometry
-- --------- ----------
1 Mainstreet SDO_GEOMETRY
2 5th Avenue SDO_GEOMETRY
and I have a table with my events, like
id routename velocity from to
-- --------- -------- ---- ----
1 Mainstreet 75mph 0.0 52.5
2 Mainstreet 45mph 52.5 102.0
3 5th Avenue 75mph 0.0 78.0
I want to get the events as standard SDO_GEOMETRIES, like:
id routename velocity geometry
-- --------- -------- --------
1 Mainstreet 75mph SDO_GEOMETRY
2 Mainstreet 45mph SDO_GEOMETRY
3 5th Avenue 75mph SDO_GEOMETRY
In ArcGis or Geomedia it is very simple to achieve that... must be possible in Oracle I guess?

Transpose without PIVOT in ORACLE

currently I am using pl/sql Developer(Oracle). I am told to convert a Row wise arranged data into columns but without the use of PIVOT. Since the Table I am working on dynamically changes, I am not able to use DECODE too.
POLICY SEQS INVDATE SUM(AMT)
-------- ------ ----------- ----------
policA 123 01-JAN-10 40
policA 123 01-FEB-10 50
policA 123 01-MAR-10 60
policA 456 01-JAN-10 360
policA 456 01-FEB-10 450
policA 456 01-MAR-10 540
policA 789 01-FEB-10 1000
polcA 789 01-MAR-10 1000
I have to re-arrange the dates and the sum of amounts column wise. So that the Single Policy and Single SEQS will have the dates and its amount column wise in a line.
"POLICY","SEQS","INST1","INST1SUM","INST2","INST2SUM","INST3","INST3SUM"
"policA","123","01-JAN-10","40","01-FEB-10","50","01-MAR-10","60"
"policA","456","01-JAN-10","360","01-FEB-10","450","01-MAR-10","540"
"policA","789","01-FEB-10","1000","01-MAR-10","1000"
Some Policy might not be starting from Jan, so the INST1 must be from feb, INST2 must be Mar and INST3 and corresponding INSTSUM must be NULL.
Is there any way that this can be done using CROSS JOINS or using xml function?
Can I use xmlagg with alternative data (INST and SUM)?
I have done some research and am not able to solve this out. Can you please help me with this?

linq group by First()

I have the following list
ID Counter SrvID FirstName
-- ------ ----- ---------
1 34 66M James
5 34 66M Keith
3 55 45Q Jason
2 45 75W Mike
4 33 77U Will
What I like to do is to order by ID by ascending and then get the first value of Counter, SrvID which are identical (if any).
So the output would be something like:
ID Counter SrvID FirstName
-- ------ ----- ---------
1 34 66M James
2 45 75W Mike
3 55 45Q Jason
4 33 77U Will
Note how ID of 5 is removed from the list as Counter and SrvID was identical to what I had for ID 1 but as ID 1 came first I removed 5.
I tried the following but not working:
var query = from record in list1
group record by new {record.Counter, record.SrvID }
into g
let winner = (from groupedItem in g
order by groupedItem.ID
select groupedItem ).First()
select winner;
I get the followng message:
The method 'First' can only be used as a final query operation.
The funny thing is the full error message is:
"NotSupportedException: The method 'First' can only be used as a final query operation. Consider using the method 'FirstOrDefault' in this instance instead."
I have had a problem with using First in Entity Framework, have you tried changing to FirstOrDefault ?

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