Ntilde entity relationship

HTML DTD with support for Style Sheets

NAMECASE GENERAL YES ENTITY NO DELIM GENERAL forward relationship type -- REV CDATA #IMPLIED -- reversed relationship type. PUBLIC "ISO //ENTITIES Added Latin 1//EN//HTML" posavski-obzor.info . Relationship values can be used in principle: a) for document. An Entity–relationship model (ER model) describes the structure of a database with the help of a diagram, which is known as Entity Relationship Diagram (ER Diagram). An ER diagram shows the relationship among entity sets. In terms of DBMS, an entity is a table or attribute of a.

URLs within the document may be in a "partial" form relative to this base address. As well as reading it, the reader may use a keyword search. The document can be queried with a keyword search by adding a question mark to the end of the document address, followed by a list of keywords separated by plus signs.

Page 18 HTML 2. The Isindex element is usually generated automatically by a server. To use the Isindex element, the server must have a search engine that supports this element. A document may have any number of Link elements. The Link element is empty does not have a closing tagbut takes the same attributes as the Anchor element.

Typical uses are to indicate authorship, related indexes and glossaries, older or more recent versions, etc. Links can indicate a static tree structure in which the document was authored by pointing to a "parent" and "next" and "previous" document, for example.

Servers may also allow links to be added by those who do not have the right to alter the body of a document. This tag takes a single attribute which is the next document-wide alpha-numeric identifier to be allocated of the form z Human writers of HTML usually use mnemonic alphabetical identifiers. HTML user agents may ignore the Nextid element. Page 19 HTML 2. The title should identify the contents of the document in a global context, and may be used in a history lists and as a label for the window displaying the document.

Unlike headings, titles are not typically rendered in the text of a document itself. The Title element must occur within the head of the document, and may not contain anchors, paragraph tags, or highlighting. Only one title is allowed in a document. The length of a title is not limited; however, long titles may be truncated in some applications.

To minimize this possibility, titles should be fewer than 64 characters. Also keep in mind that a short title, such as Introduction, may be meaningless out of context. Although it is generally preferable to use named elements that have well-defined semantics for each type of meta-information, such as a title, this element is provided for situations where strict SGML parsing is necessary and the local DTD is not extensible.

This provides document authors a mechanism not necessarily the preferred one for identifying information that should be included in the response headers for an HTTP request. Attributes of the Meta element: Page 20 HTML 2. If the semantics of the HTTP response header named by this attribute is known, then the contents can be processed based on a well-defined syntactic mapping whether or not the DTD includes anything about it.

HTTP header names are not case sensitive. Examples If the document contains: Tue, 04 Dec Example of an inappropriate use of the Meta element: Page 21 HTML 2. Some inappropriate names are "Server", "Date", and "Last-modified". Whether a name is inappropriate depends on the particular server implementation. It is recommended that servers ignore any Meta elements that specify HTTP-equivalents equal case-insensitively to their own reserved response headers.

Typically, an Address is rendered in an italic typeface and may be indented. The Address element implies a paragraph break before and after. Page 22 HTML 2. If this hypertext is selected by readers, they are moved to another document, or to a different location in the current document, whose network address is defined by the value of the HREF attribute.

In this example, selecting "HaL" takes the reader to a document at http: The format of the network address is specified in the URI specification for print readers. In this example, selecting "glossary" takes the reader to another anchor i. The NAME attribute is described below. If the anchor is in another document, the HREF attribute may be relative to the document's address or the specified base address see 2.

Page 23 HTML 2. The value of the NAME attribute is an identifier for the anchor. Identifiers are arbitrary strings but must be unique within the HTML document. Another document can then make a reference explicitly to this anchor by putting the identifier after the address, separated by a hash sign: The HTML user agent may display the title of the document prior to retrieving it, for example, as a margin note or on a small box while the mouse is over the anchor, or while the document is being loaded.

Another reason is that documents that are not marked up text, such as graphics, plain text and Gopher menus, do not have titles. The value is a comma-separated list of relationship values. Values and their semantics will be registered by the HTML registration authority. The default relationship if Berners-Lee, Connolly, et.

Page 24 HTML 2. These are more accurately given by the HTTP protocol when it is used, but it may, for similar reasons as for the TITLE attribute, be useful to include the information in advance in the link. For example, the HTML user agent may chose a different rendering as a function of the methods allowed; for example, something that is searchable may get a different icon. Page 25 HTML 2. The Blockquote element causes a paragraph break, and typically provides space above and below the quote.

A Heading element implies all the font changes, paragraph breaks before and after, and white space necessary to render the heading.

Relationships between Entities in Entity Framework 6

The highest level of headings is H1, followed by H The rendering of headings is determined by the HTML user agent, but typical renderings are: One or two blank lines above and below. Page 26 HTML 2. One blank line above and below. One blank line above. Although heading levels can be skipped for example, from H1 to H3this practice is discouraged as skipping heading levels may produce unpredictable results when generating other representations from HTML.

Like most other elements, character-level elements include both opening and closing tags. Only the characters between the tags are affected: Character-level tags may be ignored by minimal HTML applications. Character-level tags are interpreted from left to right as they appear in the flow of text. Level 1 HTML user agents must render highlighted text distinctly from plain text.

Page 27 HTML 2. If a specific rendering is necessary, for example, when referring to a specific text attribute as in "The italic parts are mandatory", a formating element can be used to ensure that the intended rendered is used where possible. Do not confuse with the Preformatted Text element. It might commonly be Berners-Lee, Connolly, et. Page 28 HTML 2. Otherwise, alternative mapping is allowed. Page 29 HTML 2. This element cannot be used for embedding other HTML text.

Note that some HTML user agents can render linked graphics but not in-line graphics. If a graphic is essential, you may want to create a link to it rather than to put it in-line. If the graphic is not essential, then the Image element is appropriate. The Image element, which is empty no closing taghas these attributes: ALT Optional text as an alternative to the graphic for rendering in non-graphical environments. Alternate text should be provided whenever the graphic is not rendered. Alternate text is mandatory for Level 0 documents.

Image maps are graphics in which certain regions are mapped to URLs. By clicking on different regions, different resources can be accessed from the same graphic. Page 30 HTML 2. Image elements are allowed within anchors. Definition lists are typically formatted with the term flush-left and the definition, formatted paragraph style, indented after the term.

Entity framework supports three types of relationships, same as database: The following figure shows the visual designer for that EDM with all the entities and relationships among them.

Hypertext Markup Language - - HTML Public Text

Let's see how each relationship association is being managed by entity framework. A student can have only one or zero addresses. Entity framework adds the Student reference navigation property into the StudentAddress entity and the StudentAddress navigation entity into the Student entity. This means that Standard can have many Teachers whereas Teacher can associate with only one Standard. To represent this, the Standard entity has the collection navigation property Teachers please notice that it's pluralwhich indicates that one Standard can have a collection of Teachers many teachers.

A chasm trap occurs when a model suggests the existence of a relationship between entity types, but the pathway does not exist between certain entity occurrences.

For example, a Building has one-or-more Rooms, that hold zero-or-more Computers. One would expect to be able to query the model to see all the Computers in the Building.

However, Computers not currently assigned to a Room because they are under repair or somewhere else are not shown on the list. Another relation between Building and Computers is needed to capture all the computers in the building. This last modelling issue is the result of a failure to capture all the relationships that exist in the real world in the model. See Entity-Relationship Modelling 2 for details.

Entity—relationships and semantic modeling[ edit ] Semantic model[ edit ] A semantic model is a model of concepts, it is sometimes called a "platform independent model". It is an intensional model. At the latest since Carnapit is well known that: The first part comprises the embedding of a concept in the world of concepts as a whole, i. The second part establishes the referential meaning of the concept, i.

Extension model[ edit ] An extensional model is one that maps to the elements of a particular methodology or technology, and is thus a "platform specific model". The UML specification explicitly states that associations in class models are extensional and this is in fact self-evident by considering the extensive array of additional "adornments" provided by the specification over and above those provided by any of the prior candidate "semantic modelling languages". It incorporates some of the important semantic information about the real world.