Database Concepts Four types of Database concepts are
Database Concepts Ø Four types of Database concepts are, 1. Hierarchical Database 2. Network Database 3. Object Oriented Model 4. Relational Database Ø Problem with both hierarchical & network database – complicated – inflexible database. Ø Database can be prepared, edited & maintained separately.
Database Concepts 1. Hierarchical Database: Ø Organize data at different levels – contain one to one relationship. Ø For Ex. in (Fig. 4. 1): A is a parent & A 1 & B 1 are child. Parent has got child. But there is no relationship between A & B also A 1 & B 1. Quadtree is a type of hierarchical type. Ø Searching fast – updating easy in hierarchical database. Ø Disadvantage – linkage – only vertically but not horizontally & diagonally.
Hierarchical Database
Database Concepts
Database Concepts 2. Network Database: Ø Linkage between a parent with children of other parent possible & flexibility exists – extent. Ø (Fig. 4. 2) Parent A & B is in relation with child 1.
Database Concepts
Database Concepts 3. Object Oriented Model: Ø Functions – model spatial & non-spatial relationships – geographic objects – attributes. Ø Encapsulated unit – characterized by attributes – a set of orientations & rules. Ø Object Oriented Model – Characterized by generic properties – abstraction – adhoc queries Ø Objects, classes & super classes are abstracted well Ø Object Orientation model exists but not – fullest capability – GIS analysis.
Database Concepts
Database Concepts Ø Data – stored – structure manner. Ø Data not arranged – proper order – not easy to analyse – unstructured data – known as flat file.
Database Concepts 4. Relational Database Concepts: Three types of relationship exists are, a) One to one b) One to many c) Many to one Ø Source table – is first table – which data – exported to other table – called destination table. Ø One to one relationship – one record – destination table – related with one record in source table.
Database Concepts Ø One to many relationship – one record in destination table – related with many record in source table. Ø Many to one relationship – many records in destination table – related with one record in the source table. Ø Data – entered by typing or exporting data from other database packages. Ø Data entered – verified with original data.
Database Concepts
Database Concepts
Flat file for a zone Parc Owner el No. Address Area Zo. Landuse Cd type 101 Karthik 20, VK road 1500 1 Agri 101 Shyam 31, Raja Rd 1500 1 Agri 102 Shivanna 1, Rajaji Rd 2200 2 Builtup 102 Ragavener 59, Kumar Rd 2200 2 Built up 103 Vivek 8, Gowda Rd 1200 2 Built up 104 Peter 4, Avenue Rd 9000 1 Agri 104 Mubarak 40, Samy coly 9000 1 Agri
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