CBSE 10th class Unit 3: Chapter 3 WORKING WITH MULTIPLE TABLES

 

Unit 3
 Chapter 3 
WORKING WITH MULTIPLE TABLES

A. Multiple Choice Questions

1.      (d) All of the above

2.      (c) Both (a) and (b)

3.      (b) Both the tables must have a common field

4.      (b) The corresponding record in the transaction table can only be entered once.

5.      (c) Many-to-many

A. Multiple Choice Questions

6. (b) One-to-many
7. (c) Tools
8. (a) Add Tables
9. (b) Drag and Drop
10. (d) Right click

B. State whether the following statements are True or False

1. False
2. True
3. True
4. False
5. True

A. Multiple Choice Questions

6. (b) One-to-many
7. (c) Tools
8. (b) The database
9. (a) A common field
10. (a) Always be deleted

B. State whether the following statements are True or False

1. False
2. True
3. True
4. False
5. True

C. Fill in the blanks

1. Datasheet view.
2. Common field between them.
3. One-to-one relationship.
4. One-to-many is one of the most common types of relationship between the tables in a database.
5. A record being entered in a transaction table must always exist in a master table.
6. The principle of referential integrity helps prevent missing data by keeping deleted data from getting out of synch.
7. Creating relationships between tables restricts the user from entering invalid data in the referenced fields.
8. Data integrity is maintained by the database.
9. A relationship between customers and products is an example of many-to-many relationship.
10. The Relationship window is used to set relationships between the tables.

D. Answer the following questions

1. Give any two advantages of relating a table in a database.
• Data Integrity: Ensures data consistency and prevents data anomalies.
• Efficient Data Retrieval: Allows for complex queries and reports by combining data from related tables.
2. How is redundancy or inconsistency controlled in a database? Explain with an example.
• Redundancy and inconsistency are controlled by normalizing the database and using relationships. For example, instead of storing customer information in multiple tables, it can be stored in a single "Customers" table. Other tables, like "Orders" and "Payments," can reference the "Customers" table using a customer ID as the common field.
3. Define referential integrity. Who maintains referential integrity in a database?
• Referential integrity ensures that data in related tables is consistent and accurate. It prevents actions that would violate the relationships between tables. The database management system (DBMS) maintains referential integrity by enforcing rules and constraints.
4. Differentiate between one to one relationship and one to many relationship. Give suitable examples to explain your answer.  
• One-to-one: Each record in one table corresponds to exactly one record in another table. Example: A person and their social security number.
• One-to-many: One record in one table can be associated with multiple records in another table. Example: A customer and their orders.
5. Explain many to many relationship with an example.
• In a many-to-many relationship, multiple records in one table can be associated with multiple records in another table. To implement this type of relationship, a junction table is often used. Example: A student and the courses they take. The junction table would store the student ID, course ID, and any additional relevant information about the student's enrollment in the course.