Subject: Computer Science
Database Management System is a software that manages data stored in the database. Example: MS-Access, FoxPro, Oracle, etc.
Data
Data are the facts or figures obtained from various sources.
Information
Information is the processed data.
Database
Database is the collection of data or related information.
Advantage of DBMS
Disadvantages of DBMS
Microsoft Access is a database management system which is used to collect, store and manage information as well as run reports. It provides facility to store the data in structured was and ways to organize the data and retrieve them as required by user. It is a relational database management system. Data are stored in more than one table to avoid data redundancy.
A field is a piece of information about an element which may be a person, student or employee.
A collection of related field is called record.
1. Table:
A table is a collection of records or group of records. A table contains a number of rows and columns.
Importance of Table
Way to create table
2. Forms:
A form is a database object which is designed to enter records and edit the existing records easily.
Importance of forms
Ways to create forms
3. Query:
A query is simply a more formal way to sort and filter data stored in the database.
Methods to create queries are :
Importance of query
Types of query
Sorting
Sorting means organization of database so that the information we need most is easily available in ascending/descending order.
Filtering
Filtering database means showing only those databases which meet certain criteria.
4. Report:
Report is a very important object of database. A report is an effective way of presenting your data in a printed format or an screen soft copy.
Importance of report
Creating report
Data type
Data type is the type which is used to declare variable names, variable types and sizes for various operations.
Data redundancy
Data redundancy means the repetition of data in a database.
Computerized database
The database which is run on computer is called computerized database.
Non computerized database
The database which is run on paper is called non computerized database.
Cell
A cell is an intersection of rows and columns.
Any raw facts or figure that may not have significant meaning by itself is known as data. Processed data or organized collection of related data which has significant meaning is known as information.
SN | Database | DBMS |
1 | Database is a collection of interrelated data | Database management system is a software which can be used to manage the data by storing it on to the data base and by retrieving it from the data base. |
2 | The database holds the records, fields, cells with data. | The DBMS is the "tools" used to manipulate the data in the database. |
3 | The examples of database are dictionary, encyclopedia etc. | The example of DBMS are MS Access, DBASE etc. |
Any four advantages of DBMS are as follows:
The list of data type are as follows:
Text
The text filed data type stores text or combinations of text and numbers.
Memo
The memo field data type stores lengthy text or combination of text and numbers.
Number
The number field data type stores numeric data that are to be used in mathematical calculations.
Byte
The byte stores numbers from 0 to 225 without decimals.
Integer
The integer number data type stores numbers from -32768 to 32767 without decimals.
Date/Time
The date/time data field stores only date and time.
Currency
The currency field data type stores currency data such as cost.
Auto Number
The auto number field data generates the unique sequential number automatically whenever a new record is added on a table.
Yes/No
The yes/no field data type stores a logical data.
OLE Object
The OLE object field data type allows a user to embed or link other objects in a table.
Hyperlink
The hyperlink filed data type stores hyperlink address, web sites, database objects or other files.
Lookup wizard
It allows to choose a value from another table or from a list of values by using list box or combo box.
Description
The description of field describes the purpose of field.
Report is a very important object of database. It is an effective way of presenting your data in a printed format or a screen soft copy.
The importance of report are as follows:
The objectives of database system are:
Select query is a most common type of query that retrives data from one or more tables and displayed the result in a datasheet. You can also use a select query to group records and calculate sums, counts and average, minimum and maximum. An action query is also type of query that makes changes or updates many records in just one operation.
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