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Microsoft Access 1. Database Creation and Management. Basic DB Terms. Data : Meaningful facts, text, graphics, images, sound, video segments A collection of individual responses from a marketing research Information : Data processed to be useful in decision making
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Microsoft Access 1 Database Creation and Management
Basic DB Terms • Data: Meaningful facts, text, graphics, images, sound, video segments • A collection of individual responses from a marketing research • Information: Data processed to be useful in decision making • Pattern of geographical buying habit based on analysis of a marketing research • Metadata: Data that describes data
Data in Context Large volume of facts, difficult to interpret & make decisions
Information Useful for decision making / interpretation
Metadata Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and documentation (Data Dictionary)
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
Database • Collection of electronic data • Central repository of shared data • Data Stored in a standardized and convenient form.
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.
Types of Databases • Databases can be classified according to: • Number of users • Database location(s) • Expected type and extent of use • Single-user database supports only one user at a time (Desktop database) • Multiuser database supports multiple users at the same time
Types of Databases • Centralized database: data located at a single site • Distributed database: data distributed across several different sites • Operational database: supports a company’s day-to-day operations • Transactional or production database • Data warehouse: stores data used for tactical or strategic decisions
Overview of Access • One of database management systems software. • Access, SQL Server, Oracle, DB 2 • MS Access is a relational model (database). • a collection of tables that are related to one another based on a common field. • Relational model – developed based on predicate logic and set theory from mathematics.
A schematic diagram of a relational database (a) and a sample part of a relational database showing different tables (b) Relational model (database)
Properties of Relation 1 • Based on the set theory 1. There are no duplicate rows. • The body of the relation is a mathematical set (i.e., a set of rows), and sets in mathematics by definition do not include duplicate elements. • If a "relation" contains duplicate rows, then it is not a relation.
Properties of Relation 2 2. Rows are unordered (top to bottom). • Sets in mathematics are not ordered. So, even if a relation A's rows are reversely ordered, it is still the same relation. • Thus, there is no such thing as "the 5th row" or the last row. In other words, there is no concept of positional addressing.
Properties of Relation 3 3. Columns are unordered (left to right). • The heading of a relation is also defined as a set. • There is no such thing as "5th column" or the last column.
Properties of Relation 4 4. Every value isatomic. • At every row-and-column position within the table, there always exists precisely one value, never a list of values. Or equivalently, relations do not contain repeating groups. ** No two rows can be identical **
Terminology Synonyms… Figure 2-6: Equivalent Sets of Terms
A Nonrelation Example Cells of the table hold multiple values
Example of a Nonrelational Table No two rows can be identical
Open an existing database • To open an existing database, you must first start Access • When Access is launched you will see the Access window, with the task pane on the right side of the window. • From the task pane, you can open an existing database. • Or simply double-click the existing database to open. • Download and save “Restaurant 1” database.
How Access creates and saves a new database • Create a new database • Your first activity (before question #1) for the midterm is creating a new database. • Database name: your last name + first initial of your first name • When you press the Save button in Access, you are saving the design of the Access objects and NOT the database itself! • The Save function in Access differs from the Save function in other Windows programs.
Valle Coffee’s Restaurant DB • Valle company sells inexpensive coffee beans to various restaurants. Barbara Hennessey, the Director of CRM, and her staff use Access to maintain company data such as customer orders and billings. Barbara has recently developed Restaurant 1 database to track orders and billings. However, she has not been able to develop the database fully to track and maintain other important company data. So, she is asking for your help in completing and maintaining the Valle database.
Descriptions of Restaurant DB • Valle coffee’s Restaurant 1 database will contain five tables: • Customer table, which Barbara already has. • Order table, which you will create soon. • Product and Order Detail tables, which you will import from FineFood database. • Billing Address table that is in Excel format and you will import it, and then convert to Access table.