[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-655948-105":59,"doc-detail-655948-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","er-diagrams-entity-relationship-model-overview","ER Diagrams - Entity Relationship Model Overview","","ER diagrams visually describe how data elements relate within database systems by modeling entity sets, relationships, and attributes. The content introduces core symbols for entities, weak entities, relationships, attributes (simple, key, derived, multivalued), and special relationship types such as weak relationships. It also covers enhanced/extended ER modeling, explaining added semantic concepts like specialization, generalization, aggregation, union/category, and how these support complex database requirements and more accurate schema representation.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/er-diagrams-entity-relationship-model-overview/655948/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/er-diagrams-entity-relationship-model-overview/655948.png","ImageObject",300,407,{"name":92,"@type":93},"Patrick","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-27","2026-10-25",true,{"@type":102,"interactionType":103,"userInteractionCount":81},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What does an ER diagram explain in database modeling?","Question",{"text":112,"@type":113},"An ER diagram explains the logical structure of databases by showing how entity sets, relationships, and attributes are connected and organized.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How are key, derived, and multivalued attributes represented?",{"text":117,"@type":113},"Key attributes are underlined inside the ellipse. Derived attributes use a dotted ellipse within the main ellipse. Multivalued attributes are shown with a double ellipse, one inside another.",{"name":119,"@type":110,"acceptedAnswer":120},"What is the difference between specialization and generalization?",{"text":121,"@type":113},"Specialization is a top-down process that breaks a higher entity into subclasses based on unique characteristics. Generalization is a bottom-up process where multiple lower-level entities combine into a higher-level entity based on shared features.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},655948,1793052813,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":81,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},549758146520,"https://ap-avatar.wpscdn.com/avatar/80002397d8c0411e94?_k=1775819394049821470","ER Diagrams  \nER Diagrams  \n􀁸 An ER diagram shows the relationship among entity sets  \n􀁸 ER Diagram is a visual representation of data that describes how data is related to each other.  \n􀁸 Entity relationship diagram displays the relationships of entity set stored in a database.  \n􀁸 In other words, we can say that ER diagrams help you to explain the logical structure of databases.  \nER diagram symbols  \n\n| Symbol | Name |\n| --- | --- |\n| | Entity |\n| | Weak Entity |\n| | Relationship |\n| | Weak Relationship |\n| | Attribute / Simple Composite / Single valued Attributes |\n| | Key Attribute |\n| | Multi valued Attributes |\n| | Derived Attributes |\n\n\n| | Partial Key Attributes |\n| --- | --- |\n| \u003Cbr>IS A | Generalization / Specialization |\n| | Total Generalization |\n| | Super class / Sub class |\n| | Union / Category |\n\nComponents of ER Diagram  \n􀁸 Entitiy, Attributes, Relationships etc form the components of ER Diagram and there are defined symbols and shapes to represent each one of them.  \nEntity  \n􀁸 Simple rectangular box represents an Entity.  \nRelationships between Entities-Weak and Strong  \n􀁸 Rhombus is used to setup relationships between two or more entities.  \n􀁸 Weak Relationships are connections between a weak entity and its owner.  \n􀁸 In above example, \"Trans No\" is a discriminator within a group of transactions inan ATM.  \nAttributes for any Entity  \n􀁸 Ellipse is used to represent attributes of any entity. It is connected to the entity.  \nWeak Entity  \n􀁸 A weak entity is a type of entity which doesn't have its key attribute.  \n􀁸 It can be identified uniquely by considering the primary key of another entity.  \n􀁸 They don't have primary keys, and have no meaning in the diagram without their parent entity.  \n􀁸 A weak Entity is represented using double rectangular boxes. It is generally connected to another entity.  \nKey Attribute for any Entity  \n􀁸 To represent a Key attribute, the attribute name inside the Ellipse is underlined.(Primary key)  \nDerived Attribute for any Entity  \n􀁸 Derived attributes are those which are derived based on other attributes, for example, age can be derived from date of birth.  \n􀁸 To represent a derived attribute, another dotted ellipse is created inside the main ellipse.  \nMultivalued Attribute for any Entity  \n􀁸 Multivalued attributes are those that are can take on more than one value.  \n􀁸 Double Ellipse, one inside another, represents the attribute which can have multiple values.  \nSample ER diagrams  \n1) Library Management System  \n2) Student management System  \n3)  \nHo  \nspit  \nal  \nMa  \nnag  \nem  \nent  \nSys  \ntem  \nAssignments on ER diagrams  \n􀁸 Employee database system  \n􀁸 Banking system  \n􀁸 Exam database system  \n􀁸 Hotel Management system  \n􀁸 Anna university database system  \n􀁸 Airline Reservation system  \n􀁸 Railway reservation system etc.,  \nEnhanced ER model / Extended ER model  \n􀁸 ER model is supported with the additional semantic concepts is called as Extended / Enhanced Entity Relationship Model  \n􀁸 EER model includes following concepts  \no Specialization  \no Generalization  \no Aggregation  \no Sub class and Super Class  \no Union or Category  \n􀁸 Enhanced entity-relationship diagrams are advanced database diagrams very similar to regular ER diagrams which represent requirements and complexities of complex databases.  \n􀁸 As the complexity of data increased in the late 1980s, it became more and more difficult to use the traditional ER Model for database modelling. Hence some improvements or enhancements were made to the existing ER Model to make it able to handle the complex applications better .  \nFeatures of EER Model  \n􀁸 EER creates a design more accurate to database schemas.  \n􀁸 It reflects the data properties and constraints more precisely.  \n􀁸 It includes all modeling concepts of the ER model.  \n􀁸 Diagrammatic technique helps for displaying the EER schema.  \n􀁸 It includes the concept of specialization and generalization.  \n􀁸 It is used to represent a collection of objects that is uni","cbCaioCPI59UVjGq","https://ap.wps.com/l/cbCaioCPI59UVjGq","pdf",1610396,25,"English","# ER Diagrams\n## ER Diagram Symbols\n## Components of ER Diagram\n## Entity Types and Attributes\n## Sample ER Diagrams\n## Enhanced ER Model (EER)\n## Features of EER Model\n## Specialization\n## Generalization","[{\"question\":\"What does an ER diagram explain in database modeling?\",\"answer\":\"An ER diagram explains the logical structure of databases by showing how entity sets, relationships, and attributes are connected and organized.\"},{\"question\":\"How are key, derived, and multivalued attributes represented?\",\"answer\":\"Key attributes are underlined inside the ellipse. Derived attributes use a dotted ellipse within the main ellipse. Multivalued attributes are shown with a double ellipse, one inside another.\"},{\"question\":\"What is the difference between specialization and generalization?\",\"answer\":\"Specialization is a top-down process that breaks a higher entity into subclasses based on unique characteristics. Generalization is a bottom-up process where multiple lower-level entities combine into a higher-level entity based on shared features.\"}]","ER Diagrams - Entity Relationship Model Overview | PDF",1792965066,63]