Sorting & Extracting Data

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Transcript of Sorting & Extracting Data

  • 1. Using Databases toFacilitate Learning and Develop Inquiry SkillsDefinitions, Planning and Design Issues,Higher-Order Thinking Skills,Advantages and Disadvantages

2. What Can You Do with aDatabase ?Databases can be used to:4 Analyze, collect, and manipulate data.4 Foster problem-solving activities(planning, organizing, categorization,dissemination, and logical thinking).4 Create an environment for inquiry.4 Classify and group data. 3. Definitions4 A database is a collection of related fieldsgrouped into records.4 Fields are the smallest unit of data and areuseless by themselves. All fields related toa particular subject form records.4 Records are used to represent all theinformation pertaining to one person,place, topic, or thing.4 The conglomeration of records forms thedatabase. 4. Steps to Complete Before Planning a DatabaseThoroughly understand:4 The data to store and manipulate.4 The interdependencies among data.4 The reason why the data exists.4 The types of problems that can be solvedusing the data.4 The ways data can be managed andmanipulated to produce a useable product. 5. Steps in Planning a Database4 Decide what data fields are needed nowand project future needs.4 Define data fields and name themappropriately.4 Establish guidelines for thecontents of each field.4 Enter data. 6. Planning the DatabaseFields contain text or numeric data. Insome databases, they can also containpictures, computations, times, or dates.The definition of fields is a critical part ofplanning the database. In order for thedatabase to be useful, it must have allinformation necessary for solving a givenproblem (i.e., many useful and relevantfields). 7. Planning the Database4 Fields should contain only one type of datain order to provide uniformity, make thedatabase easy to use, produce consistentresults from queries, and make thedatabase more reliable.4 It is best to subdivide fields for accuracyand ease-of-use. Example: Name (JohnDoe) could become Last Name (Doe) andFirst Name (John) or Size = 9lbs. 2oz. couldbe Pounds (9) Ounces(2). 8. Planning the DatabaseNaming fields is also important. Long,unrelated names should be avoided andreplaced with short, concise, and easilyunderstood titles.Examples:4 City in the USA = City4 Things birds eat = Diet4 Length of reptile = Length 9. Planning the DatabaseAfter fields have been selected andappropriately named, it is essential to analyzethe field s contents and design applicablerules or guidelines for data entry.Without guidelines or predetermined rangesfor data entry, searching and sorting thesefields will produce inconsistent andinaccurate results. 10. Some Currently AvailableDatabase Packages4 Dbase4 Oracle4 ClarisWorks4 Microsoft Works forWindows4 Access 11. Database Structures4 Hierarchical4 Relational4 Network 12. Hierarchical Databases4 This is the simplest type of database.4 The tree structure illustrates this concept. 13. Hierarchical Databases4 Information is accessed from the top tothe bottom (top-down).4 Illustrates a parent-child relationshipwhere each item relates only to the oneabove and below it.4 Disadvantage following the hierarchyis sometimes difficult, cumbersome, andtime consuming. 14. Relational Database4 Allows multiple associations usingcommon fields in multiple databases.4 Arranged in a two-dimensional tableformat.4 Files are known as relations, fields arecolumns, and records are called rows.4 Performs the following: joining, projection,and selection. 15. Relational Database4 Used in libraries effectively4 Users must define, create, and implementfiles. This is not automatically done by therelational database or databasemanagement system.4 Disadvantage: there is no way to link fieldsin a practical manner. Explicit links areformed by relations (or files rather thanspecific fields contained within files). 16. Network Databases4 These types of databases have a less rigid structures than the hierarchical model. They permit the use of pointers to establish the shortest path to specific information.4 This model is well suited fortransaction processing likethose found in banking,inventory control, and airlinereservation systems. 17. Network Databases4 Good for standardized operations.4 Disadvantage: Complex pointerimplementation makes modificationinvolved, and requires care to keepestablished links from being lost.4 When transactions are not predictableor stable, a relational database is abetter model. 18. Products from a DatabaseAfter the database has been created and dataentry has taken place, students or users canproduce reports or lists that sort, extract, andsummarize information from the database.Sort Arrange in ascending or descendingorder. ExtractProduce a subset from the collection ofinformation.Summarize Total amounts or a count of itemslocated. 19. Data Extraction Arithmeticand Boolean Operators=Equal to Not equal>Greater than>= Greater than or equal< Less than