IntroToRelationalDatabase part 1.ppt - Introduction to Relational Database ISYS 464 Introduction to Relational Model \u2022 Data is logically structured

IntroToRelationalDatabase part 1.ppt - Introduction to...

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Introduction to Relational Database ISYS 464
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Introduction to Relational Model Data is logically structured within relations. Each relation is a table (file) with named columns (attributes, fields) and rows (records). Fixed format, structured data
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Properties of a Relation Simple attribute No composite, no multivalued attribute Each relation must have a primary key: Simple or composite key May have other keys (candidate keys) Key cannot be null Cannot be duplicated
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Integrity Constraints Domain constraints Entity integrity: Primary key cannot be null, cannot be duplicated Referential integrity Other constraints
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Relational Database Design Strong entity: Create a table that includes all simple attributes Composite Weak entity: add owner primary key
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  • Spring '14
  • B MAK
  • Relational model

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