tailieunhanh - Lecture Introduction to computing - Lecture 27

This chapter define the term computer program, describe the use of flowcharts and pseudocode in programming, identify two ways in which a program can work toward a solution, differentiate the two main approaches to computer programming, list and describe three elements of object-oriented programming. | CSC 101 Introduction to Computing Lecture 27 Dr. Iftikhar Azim Niaz ianiaz@ 1 1 Last Lecture Summary I Data and Information Database and DBMS Data integrity, Garbage In Garbage Out (GIGO) Quality of Valuable Information Accuracy, Verifiable, timely, Organized Accessible, Useful, Cost-effective Hierarchy of Data Character, Field, Record, File, Database Common Field Data Types Text, Numeric, Auto Number, Currency, Counter Date, Memo, Logical, Hyperlink, Object, Attachment 2 2 Last Lecture Summary II File Maintenance Adding, Modifying and Deleting Records Validation Checks Alphabetic / Numeric, Range Consistency, Completeness, Check Digit File Processing Disadvantages Database Approach Advantages Flat File Databases Relational Databases 3 3 Objectives Overview The DBMS Is a program, or collection of programs, that allows any number of users to access and modify the data in a database Allows Entering data Updating, deleting, backup, Querying data, sorting Printing reports Supports thousands of users Includes tools to protect the data 5 Creating Tables first determine what kind of data will be stored in each table List the necessary fields Steps to define a field Descriptively name the field Specify the field type Alphanumeric, numeric, logical, date, binary, memo Determine the field size Database Dictionary A data dictionary contains data about each file in the database and each field in those files For each file, it stores details file name, description, the file’s relationship to other files, and the number of records in the file For each field, it stores details field name, description, field type, field size, default value, validation rules and the field’s relationship to other fields metadata (meta means more comprehensive) Contains details about data also contains data about programs and users keep track of who accessed data and when they accessed it crucial backbone to a DBMS only skilled professionals should update the contents Database . | CSC 101 Introduction to Computing Lecture 27 Dr. Iftikhar Azim Niaz ianiaz@ 1 1 Last Lecture Summary I Data and Information Database and DBMS Data integrity, Garbage In Garbage Out (GIGO) Quality of Valuable Information Accuracy, Verifiable, timely, Organized Accessible, Useful, Cost-effective Hierarchy of Data Character, Field, Record, File, Database Common Field Data Types Text, Numeric, Auto Number, Currency, Counter Date, Memo, Logical, Hyperlink, Object, Attachment 2 2 Last Lecture Summary II File Maintenance Adding, Modifying and Deleting Records Validation Checks Alphabetic / Numeric, Range Consistency, Completeness, Check Digit File Processing Disadvantages Database Approach Advantages Flat File Databases Relational Databases 3 3 Objectives Overview The DBMS Is a program, or collection of programs, that allows any number of users to access and modify the data in a database Allows Entering data Updating, deleting, backup, Querying data, sorting Printing reports