Author: admin
Entering Data into Table
After creating the table structure, you can enter records into the table. This is called populating the table. The records are entered into the table in similar way as data is entered into the spreadsheet. The database software also allows you to create a data ‘Form” through which you can enter or modify records very easily. Use of forms is very easy method to enter data into table.
You can also apply different validation rules on data fields. For example, you can apply a validation rule on a numeric field to accept the data between 0 to 100 values only. As you enter the data, the DBMS checks or validates the data and displays a message if data entry is invalid. The validation is very important feature because it helps to enter the correct data into the’ tables of database.
DBMS software also has important feature to import data from different files of different formats and store into the database tables as records. For example you can import data from a spreadsheet or text file into a database file.
Displaying Records
Once records are entered into tables of a database, these can be displayed again on the screen for editing or printing on the printer. If you are displaying records on the screen then you can see the data of only those records that fit on the screen. The data of all records can be displayed by scrolling up, down, right, left through scroll bars.
You can also see or print the data of selective fields of each record. Similarly the selective records can be printed or displayed by filtering the records of database. In filtering process only those records are retrieved from. the database that satisfy the given criteria or condition. It is called filter because only those records are displayed that fulfill the given criteria and remaining records that do not fulfill the criteria are filtered out. For example, displaying those records from table of “student” database that have value greater than 750 in the “marks” field.