Primary Key, Sorting, Filtering

1)     What is Primary key? Why is it needed?
Ans: Primary key is a field that uniquely identifies the record. It is needed because it neither accepts duplicate values nor  permit null values.

2)     Write any two uses of Primary key?
Ans: The uses of Primary key are:
i) To reduce and control duplication of record in a table.
ii) To set the relationship between tables.

3)     What is composite and foreign key?
Ans: The group of primary key that consists of two or more attributes is called composite key.
Foreign key is a unique field or combination of fields in linked table whose value matches with a primary key in another table.

4)     Define sorting and filtering in MS-Access
Ans: Sorting means grouping records in a particular order either in ascending or descending order based on a key field of the records. Sorting helps to locate the required records quickly.
Filtering is an option that selects the required records and displays the result.

5)     How is sorting different from filtering?
Ans: Sorting arranges the record either in ascending or descending order whereas filtering selects the required records and displays the result.

6)     What are the advantages of form over table?
Ans: The advantages of form over a table are:
i) It allows to design the layout of field on screen in any arrangement.
ii) It shows only the information we want to see.
iii) It can display one complete record at a time.

7)   How can data redundancy be controlled in MS-Access?
Ans: Data redundancy can be controlled in MS-Access by the use of “Primary Key”.