- ProjectPrometheus/AT_RecommendationPrototype . . . . 24 matches
def _addBookRelation(self, aNewBook, anIncrementPoint):
aNewBook.addBookRelation(book, self._getPrefCoef(book) + self._getPrefCoef(aNewBook))
book.addBookRelation(aNewBook, self._getPrefCoef(aNewBook) + self._getPrefCoef(book))
def _editBookRelation(self, anEditBook, anIncrementPoint):
anEditBook.addBookRelation(book, anIncrementPoint)
book.addBookRelation(anEditBook, anIncrementPoint)
self._addBookRelation(aBook, anIncrementPoint)
self._editBookRelation(aBook, anIncrementPoint)
self.bookRelation = {}
def addBookRelation(self, aBook, aRelationPoint):
if self.bookRelation.has_key(aBook):
self.bookRelation[aBook] += aRelationPoint
self.bookRelation[aBook] = aRelationPoint
return tuple(self.bookRelation)
return self.bookRelation[aBook]
for book in self.bookRelation.keys():
bookList.append((self.bookRelation[book], book))
for book in self.bookRelation.keys():
#print self.bookName, " relation : " , book.bookName, self.bookRelation[book]
if self.bookRelation[book] >= aScore:
- RelationalDatabaseManagementSystem . . . . 3 matches
A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by Edgar F. Codd.
= Relational Model =
The fundamental assumption of the relational model is that all data are represented as mathematical relations, i.e., a subset of the Cartesian product of n sets. In the mathematical model, reasoning about such data is done in two-valued predicate logic (that is, without NULLs), meaning there are two possible evaluations for each proposition: either true or false. Data are operated upon by means of a relational calculus and algebra.
The relational data model permits the designer to create a consistent logical model of information, to be refined through database normalization. The access plans and other implementation and operation details are handled by the DBMS engine, and should not be reflected in the logical model. This contrasts with common practice for SQL DBMSs in which performance tuning often requires changes to the logical model.
The basic relational building block is the domain, or data type. A tuple is an ordered multiset of attributes, which are ordered pairs of domain and value. A relvar (relation variable) is a set of ordered pairs of domain and name, which serves as the header for a relation. A relation is a set of tuples. Although these relational concepts are mathematically defined, they map loosely to traditional database concepts. A table is an accepted visual representation of a relation; a tuple is similar to the concept of row.
The basic principle of the relational model is the Information Principle: all information is represented by data values in relations. Thus, the relvars are not related to each other at design time: rather, designers use the same domain in several relvars, and if one attribute is dependent on another, this dependency is enforced through referential integrity.
Upload:Relational_key.png
에드가 코드는 IBM에서 일할 당시 하드 디스크 시스템의 개발을 하였다. 이 사람은 기존의 codasyl approach 의 navigational 모델에 상당히 불만을 많이 가지고 있었다. 왜냐하면 navigational 모델에서는 테이프 대신에 디스크에 데이터베이스가 저장되면서 급속하게 필요하게된 검색 기능에 대한 고려가 전혀되어있지 않았기 때문이다. 1970년에 들어서면서 이 사람은 데이터베이스 구축에 관한 많은 논문을 썻다. 그 논문은 결국에는 A Relational Model of Data for Large Shared Data Banks 라는 데이터 베이스 이론에 근복적인 접근을 바꾸는 논문으로 집대성되었다.
- radiohead4us/SQLPractice . . . . 2 matches
1. Find the names of all branches in the loan relation. (4.2.1 The select Clause)
16. Find all customers who have both an account and a loan at the bank. (4.6.3 Test for Empty Relations)
17. Find all customers who have an account at all the branches located in Brooklyn. (4.6.3 Test for Empty Relations)
- DatabaseManagementSystem . . . . 1 match
[RelationalDatabaseManagementSystem]
- MindMapConceptMap . . . . 1 match
ConceptMap 에서 중요한 것은 각 Concept 뿐만 아니라 Concept 과 Concept 간의 Relation 의 표현이다.
- OOP . . . . 1 match
* [Relation](관계)
- ProjectPrometheus/Iteration5 . . . . 1 match
|| Object-RDB Relation 을 위한 Gateway 작성 || 1 || . ||
- ProjectPrometheus/Iteration6 . . . . 1 match
|| Object-RDB Relation 을 위한 Gateway 작성 || 1 || . ||
- Spring/탐험스터디/wiki만들기 . . . . 1 match
* ORM(Object Relation Mapping) 프레임워크. Java persistence, EJB3.0을 같이 알면 좋다.
- java/reflection . . . . 1 match
* ORM(Object-Relational-MApping)이 아닌 방식으로 DAO를 만들 때 사용되기도 한다.
- 졸업논문/참고문헌 . . . . 1 match
[11] "A Relational Model of Data for Large Shared Data Banks", E. F. Codd , Communications of the ACM, Vol. 13, No. 6, June 1970, pp. 377-387.
Found 11 matching pages out of 7544 total pages (5000 pages are searched)
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