10th Class Computers Science Microsoft Access Data validation

  Data validation

MS Access allows checking data validity on data insertion time. You can apply your own validation rule.  

 There are two types of data validation Field Level Allows validating data being inserted in an individual field.  

• Record Level Allows validating data from more than one field.
• MS Access enables the following validation techniques and methods:  

 Data Types

It is the simplest forms of data validation. Access allows entering data according to data type of field. It does not allow entering incorrect type of data in a field.  

 Input Mask Property

It is helpful to make data entry easier and to control the values user can enter in a text box.  

  Validation Rule and Text Property

Validation rules validate data while adding, modifying or saving data in a field. Validation Text specifying the text of the message that appears if the field, control or record does not satisfy.  

 Allow Zero Length Property

Allow Zero Length property is used to specify a zero length string (" ") a valid entry in a field. This property applies only to Text, Memo and Hyperlink table field. Some time you require to store a zero length string instead of a Null value while leaving a field blank. In this case you need to set the Allow Zero Length and Required properties to yes.    

 MS Access enables various ways to create a table. Which one of the following provides step by step approach to create table?

(A) Datasheet                                                   

(B) Design view

(C) Wizard                                          

(D) All of these

(E) None of these

Answer: (c)

Explanations

Correct Option:

(C) MS Access enables a table wizard that provides a step - by- step approach to create a table. It guides you through the entire wizard/ and on the basis of your specifications it creates a table.

Incorrect Options:

Therefore, option (C) is correct and rest of the options is incorrect.  

 MS Access allows data validity on data insertion time. Which one of the following levels allows validating data from more than one field?

(A) Field level                                                   

(B) Record level

(C) Table level                                                  

(D) All of these

(E) None of these

Answer: (c)

Explanatory

Correct Option:

(C) Field level allows validating data being inserted in an individual field.

Incorrect Options:

Therefore, option (C) is correct and rest of the options is incorrect.  

 Allow Zero Length property is used to specify a zero length string (" ") a valid entry in a field. This property applies only to........................

(A) Text                                                               

(B) Memo

(C) Hyperlink                                                     

(D) All of these

(E) None of these  

Answer: (d)

Explanation

Correct Option:

(D) Allow Zero Length property applies only to Text, Memo and Hyperlink table field.

Incorrect Options:

Therefore, option (D) is correct and rest of the options is incorrect.  

• MS Access gives best compatibility with Windows operating system.  

• End User: Is a person who interacts directly with the DBMS through client software.
• Database Administrator (DBA): Is a person responsible for implementing the database management system within an organization.
• Application programmer: Is a person who develops the applications that is used to interact with the data.
• Domain: Describes the set of possible values for a given attribute.
• Tuple: Represents an object and information about the object.
• Primary Key: Is an attribute that contains unique value.
• Unique Key : Is an attribute that contains unique value. Unique key can contain NULL.  

• Database Management System is a program which retrieves, modifies and stores the data in database on request.
• RDBMS creates relationship between two or more tables.
• While designing the tables of a database, you need to enforce the data integrity in the database.
• Using Access you can enter, sort and retrieve data, extract subsets of data based on specific criteria, create user- friendly forms and customized reports.
• Table is a structure of rows and columns that stores information in logical manner.
• Allow Zero Length property is used to specify a zero length string (" ") a valid entry in a field.
• A complete DBMS includes software and hardware utilities, procedures, data and users.
• The total number of attributes or columns which compromise a table is called the degree of the table.
• MS Access allows checking data validity on data insertion time.  

 Abbreviations

DBMS                    -              Database Management System

RDMBS                 -              Relational Database Management System