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SQL and RelationalDatabase ManagementSystemsIN THIS CHAPTERUnderstanding databasesCharacteristics of a gooddatabaseThe database marketReal-life databa

Part I SQL Basic Concepts and Principlesthem into tables (think of a file cabinet) alleviates the problem somewhat but does not removethe major obstacl

SQL and Relational Database Management Systems 1FIGURE 1-1Hierarchical structureROOTCHILD 3/LEVEL 1CHILD 2/LEVEL 1CHILD 1/LEVEL 1CHILD 1/LEVEL 2CHILD

Part I SQL Basic Concepts and PrinciplesFIGURE 1-2Hierarchical database exampleORDER_HEADERPRODUCTCUSTOMEREverything works great as long as you are wi

SQL and Relational Database Management Systems 1FIGURE 1-3Network database exampleORDER HEADERPRODUCTSALESMANCUSTOMERIn addition to the ability to han

Part I SQL Basic Concepts and PrinciplesThe common misconception is that the term ‘‘relational’’ comes from the relation-ships between tables. In fact

SQL and Relational Database Management Systems 1The process of grouping the relevant data together, eliminating redundancies alongthe way, is calledno

Part I SQL Basic Concepts and Principleswarn you if you create a table without defining a primary key. Some purists go even further, spec-ifying that t

SQL and Relational Database Management Systems 1The development of relational databases was driven by the needs of big businesses for a mediumto gathe

Part I SQL Basic Concepts and PrinciplesXML is discussed in Chapter 15, ‘‘XML and SQL.’’XML first became a part of SQL standards in 2003. SQL:2003 cont

SQL and Relational Database Management Systems 1add 10 identical records for Wile Electronics Inc., completely redundant except for the shippingaddres

Part I SQL Basic Concepts and PrinciplesSufficient capacityA database’s primary function is to store large amounts of information. For example, an orde

Part I SQL Basic Concepts and PrinciplesFIGURE 1-6Primary/foreign key relationship between tablesCUSTOMERCUST_ID_NCUST_NAME_SADDRESSADDR_ID_NADDR_CUST

SQL and Relational Database Management Systems 1computer language to access the data. The problem was that IBM already had declared its ownproduct, ca

Part I SQL Basic Concepts and Principlesdevelopments. In 1984, the standard was redesigned to be more generic, to allow for morediversity among databa

SQL and Relational Database Management Systems 1SQL:1999 (SQL3)SQL:1999 represented the next step in SQL standards development. The efforts to define t

Part I SQL Basic Concepts and PrinciplesAs of this writing, all major database vendors (Oracle, DB2, and Microsoft SQLServer) have at least partial co

SQL and Relational Database Management Systems 1ScalabilityDatabases must be flexible and easily adaptable to changing business needs. That primarilyme

Part I SQL Basic Concepts and PrinciplesSelecting Your Database SoftwareEvery single DBMS on the market follows essentially the same basic principles.

SQL and Relational Database Management Systems 1Skills are a different story. Database expertise is a costly thing and usually is in short supply.On a

Part I SQL Basic Concepts and Principlesthe American National Standards Institute (ANSI) and the International Organization for Stan-dardization (ISO)

SQL and Relational Database Management Systems 1Real-Life Database ExamplesTo say that databases are everywhere would be an understatement. They virtu

Part I SQL Basic Concepts and PrinciplesSee Appendix B and Appendix F for more detailed descriptions of the ACME sampledatabase and how to install it.

SQL and Relational Database Management Systems 1Scientific databaseA database for genome research and related research in molecular and cellular biolog