CS database
functions
- Specifies which records should be retrieved by specifying criteria. - Can specify the fields to be displayed.
funtions
- To retrieve and maintaining, viewing and printing records in a database. - allows viewing data one record at a time.
function
- to design a report on the screen, - to retrieve data into the report design, - to display or print the data in the database
define and sate the function of table
A collection of records that identify a category of data
funtions
To arrange data in rows and columns. To describe the characteristics of data
state all of the database object
table,queries,forms, reports
what is field name?
uniquely identifies each field.
differentiate data and information
data is Collection of unprocessed items, information is processed data
what is foreign key?
is an attribute whose values match the primary key values in the related table, We can have more than one Foreign key in a table.
what is primary key
A field that uniquely identifies each record in a file, Also called the key field., We can have only one Primary key in a table.
what is record?
A group of related fields in a database, Also known as rows, Contains data about a given person, product, object or event.
define EDR
is a tool that graphically shows the connections among entities in a system
Describe advantages of database.
1.Avoid data redundancy because the same data fields are not repeated in the database 2. Increased data consistency by reducing updating error 3. Improved data security by providing access to authorize user
Describe disadvantages of database.
1.Database systems are complex, difficult, and time consuming to design 2.Higher setup cost for hardware and software 3.Database corruption will affects the whole system because the system is centralized.
define file-based system
A collection of application programs that perform services for the users wishing to access information.
define and sate the function of table
A collection of records that identify a category of data,such as Students,
define and sate the use of report
A report generator allow users to design a report on the screen, retrieve data into the report design and then display or print the report.
define and sate the function of query
A request for specific data from the database (retrieve data)
what is table?
A set of related records Also called files, Organized in rows and column, Contain fields and records.
what is field?
A single item of data common to all records, Also known as a columns. Contains a specific category of data within a record. represents an attribute (description or characteristic) of some entity (person, place, thing or object)
Define Database Management System
A software system that enables users to define, create, and maintain the database and provides controlled access to this database.
define and sate the function of form
A window on the screen that provides areas for entering or modifying data in a database
Definition of Entity
An entity is an object in the system that has data
what is database?
An integrated collection of logically related table.
Define database and
Collection of data organized in a manner that allows access, retrieval, and use of the data.
Definition of Relationship
Connections among entities in a system
Why file base become unpopular?
Data redundancy because of data duplication of each department thus causing redundancy and space wastage, data isolation becauseData is store in separate files in different department It is difficult to access data from a different department
what is the function of data dictionary?
Ensures that data being entered into the database does not violate any specified criteria.
state the purpose of database
Keep records of : Clients Staff Student Keep sales records, Develop reports;
what is characteristic?
Most basic element of data .
state all types of entity relationship
One-to-one (1:1) One-to-many (1:M) Many-to-many (M:N)
define data dictionary
Repository of all data definitions in a database, include data about the data:table structure,relationship between data
what the fucntion of data function
Specifies the kind of data a field can contain and how the field is used.
state data hierarchy
Tables (files), Records (rows), Fields (columns), Characters
state all the data type
Text / Alphanumeric, Numeric(number only), Currency, Yes/No (also called Boolean), Date, Memo, Hyperlink, Attachment,
what is field size?
defines the maximum number of characters a field can contain
state Difference Between File Base System and DBMS
for file based system, Data in a file based system is stored in a separate file in different department for database system The data in a database environment is centralized and shared usually over a network, by the entire organization
What are Database objects?
several tools that allow users and program to retrieve and maintain data in a database
for example
spreadsheet software
for example
spreadsheet software to manage data of employee, word processing to create sales report