Converting ER Diagrams to Tables in DBMS Converting ER Diagrams to Tables Following rules are used for converting an ER diagram into tables. Rule-01: Convert strong entity into a table A strong entity set with only simple attributes will directly convert into one table. All Attributes of the entity set will be the attributes of the table. The primary key…
Read moreE. R. Model (entity-relationship model) (E-R Diagram) in DBMS Features of E. R. Model (entity-relationship model) (ER DIAGRAM):- 1. Represented by E.R. diagram which is easy to use graphical tool for modeling data. 2. GUI representation of the logical structure of a Database. 3. easily converted into relations (tables)in the relational model. 4…
Read moreRoles in E-R Diagrams in DBMS Roles in E-R Diagrams · It is a function that plays(relationship) in an entity called its role . · Roles are normally explicit and not specified. · Useful when the relationship meaning needs to clarify. · Example, The relationship works-for define in employees as manager or worker. The…
Read moreMapping Cardinalities (Dependencies) in DBMS Mapping Cardinalities ( Dependencies ) Cardinality defines the number of entities of one entity set, which are associated or join with the number of entities of another set via a relationship set. One-to-one – · One entity from entity set A can be associated with only one entity of entity set B an…
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