Database Chapter Three OutlineSQLSQL names are case insensitive 不区分大小写Data Definition Language Create Table ConstructAn SQL relation is defined using the create tablemand:create table r (A1 D1,
Database Chapter Seven OutlineTrivial:A functional dependency is trivial if it is satisfied by all instances of a relationClosure:The set of all functional dependencies logically implied by F is the
Database Chapter Six OutlineDesign ProcessConceptual-design --- Chooses a data model, translates the requirements into a conceptual schema of databaseRedundancyIpletenessModelingA database can b
DataBase Chapter Two OutlineThe set of allowed values for each attribute is called the domain of the attributer(R) is a relation on the relation schema R Example:customer (Customer_schema)About Key:
Database Chapter Four OutlineChapter 4:Advanced SQLSQL Data Types and SchemasEXACT(field from d)CAST e AS tcreate type Dollars as numeric (12,2) finalcreate domain person_name char(20) not nullTypes
Database Chapter One OutlineA database is a collection of interrelated data itemsRelated to some enterprise, organizations,…Interrelated data itemsGracefully organizedEasy to accessA DBMS (DataBase
Chapter three verbalmunication Agenda Concept of language Is a symbolic code ofmunication consisting of a set of sounds (phonetics)with understood meanings and a set of rules (grammar) for con
Romanticism:《奇异怪诞故事集》《诗歌原理》 3) A poem must be pure written for its own sake. 4) The chief aim of a poem is to produce a sense of beauty. The aim of the poem is to elevate the soul a goal that could b
Chapter 21Industrialization spread to western and central Europe and North America, as new inventions and scientific discoveries made those that had earlier turned Britain into the first industrial na
Specifying Updates in SQLRelational Views in SQLCreating Indexes in SQLEmbedding SQL in a Programming LanguageRecent Advances in SQLDROP TABLE:Used to remove a relation(base table) and its definitionT
违法有害信息,请在下方选择原因提交举报