* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download database system
Survey
Document related concepts
Commitment ordering wikipedia , lookup
Global serializability wikipedia , lookup
Microsoft SQL Server wikipedia , lookup
Encyclopedia of World Problems and Human Potential wikipedia , lookup
Microsoft Access wikipedia , lookup
Entity–attribute–value model wikipedia , lookup
Serializability wikipedia , lookup
Extensible Storage Engine wikipedia , lookup
Oracle Database wikipedia , lookup
Open Database Connectivity wikipedia , lookup
Functional Database Model wikipedia , lookup
Ingres (database) wikipedia , lookup
Microsoft Jet Database Engine wikipedia , lookup
Concurrency control wikipedia , lookup
Relational model wikipedia , lookup
Clusterpoint wikipedia , lookup
Transcript
CSCI 150 Database Applications Chapter 1 – Getting Started CSCI 150 – Database Apps Database processing is the heart of all applications today The knowledge gained in this course will be valuable at job-hunting time Internet technology has tremendously amplified the need for database knowledge Technology can be used inside organizations as well as outside for e-commerce applications 2 Chapter 1 Objectives Know the potential problems with lists Understand the reasons for using a database Understand how related tables avoid the problems of lists Learn the components of database system Learn the elements of a database Learn the purpose of the database management system (DBMS) Understand the functions of a database application 3 Purpose of a Database The purpose of a database is to keep track of things Unlike a list or spreadsheet, a database may store information that is more complicated than a simple list 4 Problems with Lists: Redundancy In a list, each row is intended to stand on its own. As a result, the same information may be entered several times For Example: A list of Projects may include the Project Manager’s Name, ID, and Phone Extension. If a particular person is managing 10 projects, his/her information would have to be entered 10 times 5 List Modification Issues Redundancy and multiple themes create modification problems Deletion problems Update problems Insertion problems 6 List Modification Issues 7 Addressing the Information Complexities Relational databases are designed to address many of the information complexity issues 8 Relational Databases A relational database stores information in tables. Each informational topic is stored in its own table In essence, a relational database will break-up a list into several parts. One part for each theme in the list A Project List would be divided into a CUSTOMER Table, a PROJECT Table, and a PROJECT_MANAGER Table 9 Relational Database Example 10 A Relational Database Solves the Problems of Lists 11 12 13 14 15 16 Database Systems The four components of a database system are: Users Database Application Database Management System (DBMS) Database 17 Components of a Database System 18 Users A user of a database system will Use a database application to track things Use forms to enter, read, delete and query data Produce reports 19 Database Applications A database application is a set of one or more computer programs that serves as an intermediary between the user and the DBMS 20 Functions of Database Applications Create and process forms Process user queries Create and process reports Execute application logic Control database applications 21 Functions of Database Applications 22 23 24 Database Management System (DBMS) A database management system (DBMS) serves as an intermediary between database applications and the database The DBMS manages and controls database activities The DBMS creates, processes and administers the databases it controls 25 Functions of a DBMS Create databases Create tables Create supporting structures Read database data Modify database data (insert, update, delete) Maintain database structures Enforce rules Control concurrency Provide security Perform backup and recovery 26 The Database A database is a self-describing collection of related records Self-describing The database itself contains the definition of its structure Metadata is data describing the structure of the database data Tables within a relational database are related to each other 27 Desktop Database Systems Desktop database systems typically: Have one application Have only a few tables Are simple in design Involve only one computer Support one user at a time 28 Desktop Database Systems 29 Organizational Database Systems Organizational database systems typically: Support several users simultaneously Include more than one application Involve multiple computers Are complex in design Have many tables Have many databases 30 Organizational Database Systems 31 Commercial DBMS Products Example Desktop DBMS Products Microsoft Access Example Organizational DBMS Products Oracle’s Oracle Microsoft’s SQL Server IBM’s DB2 32