Each of the concepts in SNOMED CT has the conceptId (SNOMED_CID). Could you please let me know how SNOMED CT defines the SNOMED_CID. Is there any numbering scheme that SNOMED CT follows? SNOMED terms are also available in UMLS. What numbering scheme UMLS follow to define UMLS CUI?
A SNOMED CT concept identifier is a 6-digit to 18-digits string of the form
<ITEM-ID><NAMESPACE-ID><N>0<D>
where
<ITEM-ID> is the 'actual identifier' identifying the concept within the provider,
<NAMESPACE-ID> is either empty string ( <N> is a single digit 0 ) and the concept was issued by SNOMED International; or a 7-digit namespace identifier ( <N> is a single digit 1 ) issued by SNOMED International to an organization permitted to create and manage their own SNOMED concepts (extension).
<D> is a single check digit computed by https://en.wikipedia.org/wiki/Verhoeff_algorithm
For example, 1290023401004 is a valid SNOMED concept identifier created by SNOMED international (<N> is 0) with item id 1290023401, while 11000001102 is a valid SNOMED concept identifier created by NHS Digital (namespace 1000001, see https://cis.ihtsdotools.org/info/index.html?home=namespaces
, <N> is 1) with item id 1.
Details on SNOMED identifiers can be found in https://confluence.ihtsdotools.org/display/DOCRELFMT/6+SNOMED+CT+Identifiers.
Related
Am a newbie in Microsoft Access 2016 making a database system for processing loans.
I have made two fields:
ID e.g: 001 with datatype number and
NRC (This is the official National Registration Card number in my country e.g: "123456/78/1" )
I now want to generate a new field:
LoanNumber from the fields 1. ID and 2. NRC mentioned above.
From the examples above, I want this new field to be composed with two parts concatenated together; that is "ID-first part of NRC before the first '/' ".
e.g: LoanNumber : 001-123456
What code in the expression builder will will help me achieve this?
A number datatype value cannot be saved with preceding zeros. Use Format function to manipulate number. This can be done in a query or textbox but not in table because Format function is not available for Calculated field type.
Format([ID], "000-") & Left([NRC], 6)
I ran the following DMV query on SSAS.
SELECT
[HIERARCHY_UNIQUE_NAME],
[LEVEL_NAME],
[LEVEL_NUMBER],
[LEVEL_CARDINALITY],
[LEVEL_TYPE]
from $system.mdschema_levels
where [DIMENSION_UNIQUE_NAME] = '[DATE]'
AND [CUBE_NAME] = 'Adventure Works'
AND [LEVEL_NAME] <> '(All)'.
I get a lot of unexpected LEVEL_TYPES
I wanted to understand what do the LEVEL_TYPE like 4289, 4578, 4385, 4759 signify? Are they computed algorithmically or is they a documentation resource one can refer to?
These Level_TYPE are determined the "Type" property of the dimension attribute that you set in dimension design window of your SSAS project. In case if you set the Type to regular you get 0 else , if you select from one of the types present you get its identifier. The interesting bit is if the HIERARCHY_UNIQUE_NAME has a attribute hierarchy, it returns the identifier for the attribute hierarchy, if HIERARCHY_UNIQUE_NAME has user hierarchy, then the identifier is returned for the LEVEL_NAME's base attribute. For example in the result below, take a look at the two rows that return 68 in LEVEL_TYPE, the first row is being reported as attribute hierarchy, the second as user hierarchy's level(Notice the Level_Number 3 and the difference between the HIERARCHY_UNIQUE_NAME and LEVEL_NAME)
Edit: Specific type details
4289: type Date,
4578: type QuaterOfYear,
4385: type HalfYearOfYear,
4759: type WeekOfYear
Anyone Could Describe for me what is the meaning of QTY > QTY(500) in following sentence?
CONSTRAINT DBC1 IS_EMPTY
((S JOIN SP) WHERE STATUS<20 AND QTY>QTY(500));
I translate it: status is lower than 20 and quantity is bigger that 500.
please note that just I need meaning of QTY> QTY(500)...
(S JOIN SP) contains a tuple for each shipment, and this tuple is "extended" with the details of the supplier, such as his status code.
The [result of the restriction defined by the] WHERE clause thus amounts to "shipments of quantity >500 whose corresponding supplier's status is <20".
The declaration overall thus says "there cannot be any shipments of quantity >500 whose corresponding supplier's status is <20.
I have this query:
SELECT last_name, SCORE(1)
FROM Employees
WHERE CONTAINS(last_name, '%sul%', 1) > 0
It produces output below:
The question is:
Why does the SCORE(1) produce 9? As I recall that CONTAINS function returns number of occurrences of search_string (in this case '%sul%').
I expect the output should be:
Sullivan 1
Sully 1
But when I try this syntax:
SELECT last_name, SCORE(1)
FROM Employees
WHERE CONTAINS(last_name, 'sul', 1) >0;
It returns 0 rows selected.
And can someone please explain me what is the third parameter for?
Thanks in advance :)
The reason your second query is returning no rows is, you are looking for word sul in your search. Contains will not do pattern search unless you tell it to, it searches for words which you specified as your second paramter. To look for patterns, you will have to use wildcards, as you did in your first example.
Now, coming to the third parameter in CONTAINS - it is label and is just used to label the score operator. You should use the third parameter when you use SCORE in your SELECT list. It's importance is more clear when there are multiple SCORE operators
Quoting directly from documentaion
label
Specify a number to identify the score produced by the query.
Use this number to identify the CONTAINS clause which returns this
score.
Example
Single CONTAINS
When the SCORE operator is called (for example, in a SELECT clause),
the CONTAINS clause must reference the score label value as in the
following example:
SELECT SCORE(1), title from newsindex
WHERE CONTAINS(text, 'oracle', 1) > 0 ORDER BY SCORE(1) DESC;
Multiple CONTAINS
Assume that a news database stores and indexes the title and body of
news articles separately. The following query returns all the
documents that include the words Oracle in their title and java in
their body. The articles are sorted by the scores for the first
CONTAINS (Oracle) and then by the scores for the second CONTAINS
(java).
SELECT title, body, SCORE(10), SCORE(20) FROM news WHERE CONTAINS
(news.title, 'Oracle', 10) > 0 OR CONTAINS (news.body, 'java', 20) > 0
ORDER BY SCORE(10), SCORE(20);
The Oracle Text Scoring Algorithm does not score by simply counting the number of occurrences. It uses an inverse frequency algorithm based on Salton's formula.
Inverse frequency scoring assumes that frequently occurring terms in a document set are noise terms, and so these terms are scored lower. For a document to score high, the query term must occur frequently in the document but infrequently in the document set as a whole.
Think of a google search. If you search for the term Oracle you will not find (directly) any result that may help to explain your scoring value questioning, so we can consider this term a "noise" to your expectations. But if you search for the term Oracle Text Scoring Algorithm you will find your answer in the first google result.
And about your other questionings, I think that #Incognito already gives them a good answer.
I need some help converting an SQL query into relational algebra.
Here is the SQL query:
SELECT * FROM Customer, Appointment
WHERE Appointment.CustomerCode = Customer.CustomerCode
AND Appointment.ServerCode IN
(
SELECT ServerCode FROM Appointment WHERE CustomerCode = '102'
)
;
I'm stuck because of the IN subquery in the above example.
Can anyone demonstrate for me how to express this SQL query in relational algebra?
Many thanks.
EDIT: Here is my proposed solution in relational algebra. Is this correct? Does it reproduce the SQL query?
Scodes ← ΠServerCode(σCustomerCode='102'(Appointment))
Ccodes ← ΠCustomerCode(Appointment ⋉ Scodes)
Result ← (Customer ⋉ Ccodes)
Your SQL code will result in duplicate columns for CustomerCode and the use of SELECT [ALL] is likely to result in duplicate rows. Because the result is not a relation, it cannot be expressed in relational algebra.
These problems are easily fixed in SQL:
SELECT DISTINCT *
FROM Customer NATURAL JOIN Appointment
WHERE Appointment.ServerCode IN
(
SELECT ServerCode FROM Appointment WHERE CustomerCode = '102'
)
;
You didn't specify which relational algebra you are intereted in. Date and Darwen proposed an algebra named A, specified an A language named D, and designed a D language named Tutorial D.
Tutorial D uses operators JOIN for natural join, WHERE for restriction and MATCHING for semijoin, The slight complication is the comparison in SQL:
CustomerCode = '102'
The comparison of a CustomerCode value to a CHAR value in SQL is possible because of implicit coercion. Tutorial D is stricter -- type safe, if you will -- requiring you to overload the equality operator or, more practically, define a selector operator for CHAR, which would typically have the same name as the type.
Therefore, the above (revised) SQL may be written in Tutorial D as:
( Customer JOIN Appointment )
MATCHING ( ( Appointment WHERE CustomerCode = CustomerCode ( '102' ) ) { ServerCode } )
"How do I represent my query in this standard form of RA?"
It's not so much a question of "type of algebra" as it is of "type of notation".
Notation using greek symbols typically uses sigma, the restrict condition in subscript appended to the sigma character, and then the subject of the restriction (the relational expression that is subjected to the restrict condition).
Date avoid that notation, because typesetting and/or creating text using such notations is usually a lot harder than it is using just the western alphabet (a math teacher of mine once told us that math textbooks contain the most errors of all).
σ <cond> (<rel exp>) thus denotes the very same algebra expression as (Date's syntax) "<rel exp> WHERE <cond>".
Similarly, with greek symbols, projection is typically denoted using the letter Pi, with the list of retained attributes in subscript appended to the Pi, and the expression that is the subject of the projection following that.
Π <attr list> (<rel exp>) thus denotes the very same algebra expression as (Date's syntax) "<rel exp> { <attr list> }".
The join family of operators is usually denoted, in "greek" symbols, using (variations of) the Unicode BOWTIE character, or that character consisting of a lowercase letter 'x' surrounded by a full circle (usually used to denote full cartesian product, cross-product, ... whatever your algebra course happens to name it).
Some courses provide a "greek-symbol" notation for rename, using the greek letter Rho. Appended in subscript is the rename list, in the form a1->b1,a2->b2,... Appended after that comes the relational expression that is subjected to the rename. Likewise, Date has a non-greek-symbol equivalent syntax : <rel exp> RENAME a1 AS b1, a2 AS b2 , ...
The important thing is to see that these differences are merely differences in syntactical notation, not "different algebrae".
EDIT
One could imagine that the greek symbols notation would be the way to program relational algebra into an APL engine, Date's syntax would be the way to program relational algebra into a cobol-like or PL/1-like engine (there effectively exists such an engine called Rel), and the way to program relational algebra into an OO-like engine, could look something like relation.NaturalJoin(otherRelation).Matching(yetOtherRelation.Restrict(condition).project(attributesList)).