UNIT 3: DATABASE MANAGEMENT SYSTEM USING LIBREOFFICE BASE
Complete Study Material, Q&A, and PYQ Variations
How to use this book & Unit Map
Instructions: First learn the key terms and differences, then practise the short answers and case-based questions. For a 2-mark answer, give a definition plus one clear point/example. For 4 marks, answer every sub-part separately. Questions marked "PYQ pattern" cover concepts that appeared in the shared 2025/2026 papers, including scenario-based variations.
Unit map:
• Chapter 8: Introduction to DBMS
• Chapter 9: Starting with LibreOffice Base
• Chapter 10: Working with Multiple Tables
• Chapter 11: Queries in Base
• Chapter 12: Forms and Reports
CHAPTER 8 - INTRODUCTION TO DATABASE MANAGEMENT SYSTEM
A. Core concepts and definitions
1. Q. What is data?
Answer: Data consists of raw facts about people, places, objects or activities. Examples: individual student marks, names, prices and temperatures.
2. Q. What is information?
Answer: Information is data that has been processed or organised into a meaningful and useful form. Example: individual subject marks are data; a prepared report card showing total and percentage is information.
3. Q. Differentiate between data and information.
Answer: Data is raw and may not be meaningful by itself; information is processed/organised data that conveys meaning. Example: 72, 81 and 67 are marks (data); their total and average are information.
4. Q. What is a database?
Answer: A database is an organised collection of logically related data items that can be stored, searched, added, modified, deleted and retrieved as required.
5. Q. What is DBMS? Give examples.
Answer: A Database Management System (DBMS) is software used to create, store, organise, update and retrieve data from a database. Examples include LibreOffice Base, MS Access, MySQL and Oracle.
6. Q. Why is a telephone directory considered a simple database?
Answer: It stores related contact details in an organised way, such as names and phone numbers, so that a required number can be found quickly.
7. Q. State any four advantages of a DBMS.
Answer: Organised and fast retrieval; reduced data redundancy; improved consistency and accuracy; controlled data sharing; validation of data; and improved security. Any four earn full credit.
8. Q. What is data redundancy?
Answer: Data redundancy means unnecessary repetition of the same data in more than one place or table. A DBMS can reduce it by storing common details once and relating tables.
9. Q. What is data inconsistency?
Answer: Data inconsistency occurs when repeated copies of the same information do not match. For example, a student's address is updated in the admission table but remains old in the library table.
10. Q. How does a DBMS improve data validity?
Answer: Field properties and validation rules can be set so that only acceptable values are entered, for example, restricting a fee field to values above a specified minimum.
11. Q. How does a DBMS help with security?
Answer: Access can be restricted through permissions/passwords and data may be protected using encryption, preventing unauthorised users from reading or changing it.
12. Q. What is a data model?
Answer: A data model describes how data is structured, stored, related and retrieved in a database.
13. Q. Name three data models in the unit and explain them.
Answer: Hierarchical: records are arranged in a tree-like parent-child structure. Network: records can be linked through multiple connections, allowing more complex links. Relational: data is stored in tables linked through common fields.
14. Q. What is the relational database model and who proposed it?
Answer: The relational model stores data in tables of rows and columns and relates tables through common fields. The unit attributes its proposal to E. F. Codd in 1970.
15. Q. What is an entity? What is an attribute?
Answer: An entity is a real-world object about which data is stored, such as Student. An attribute is a property of that entity, such as Student_ID, Name or Date_of_Birth.
16. Q. Define table, field and record.
Answer: A table is a collection of logically related records. A field/column/attribute stores one category of data. A record/row contains the values for all fields relating to one person or object.
17. Q. What are data values?
Answer: Data values are the actual raw values stored in fields, such as 'Riya', 16, 85.5 or 2026-04-12.
18. Q. What is a relational database?
Answer: It is a database made up of related tables. The tables are connected through common fields so related information can be retrieved together.
19. Q. What is a primary key?
Answer: A primary key is a field, or combination of fields, that uniquely identifies every record in a table. Its values must be unique and cannot be left blank.
20. Q. What is a composite key?
Answer: A composite key is a key formed by combining two or more fields to identify a record uniquely. Example: Student_ID plus Subject_Code, when neither field alone uniquely identifies each marks record.
21. Q. What is a foreign key?
Answer: A foreign key is a field in one table that refers to a key in another table and is used to establish a relationship between them.
22. Q. What is a candidate key?
Answer: A candidate key is any field or combination of fields that is eligible to uniquely identify a record; its values must be unique and non-null.
23. Q. What is an alternate key?
Answer: An alternate key is a candidate key that was not selected as the primary key.
24. Q. Differentiate between primary key and foreign key.
Answer: Primary key uniquely identifies records in its own table and cannot be null or duplicated. Foreign key links to a key in another table; it can repeat, and its values must satisfy the relationship's referential rules.
25. Q. Differentiate between candidate key and alternate key.
Answer: All eligible unique identifiers are candidate keys. Once one is chosen as the primary key, the remaining candidate keys are alternate keys.
26. Q. What are the main objects of an RDBMS?
Answer: Table, Query, Form and Report. Tables store data; queries retrieve selected data; forms provide a user-friendly interface for entering/viewing data; reports present data in a formatted, readable layout.
27. Q. What is a query?
Answer: A query is a question or request made to a database to retrieve particular information according to specified fields and criteria.
28. Q. What is a form?
Answer: A form is a user-friendly screen for entering, viewing or modifying data stored in tables. It may contain labels, text boxes, list boxes, radio buttons and check boxes.
29. Q. What is a report?
Answer: A report presents data from a table or query in a structured, formatted and easy-to-read layout, suitable for printing or sharing.
B. Frequently tested differences
| Term 1 | Term 2 | Main difference |
|---|---|---|
| Data | Information | Raw facts vs processed/meaningful facts. |
| Field / Column | Record / Row | One attribute of data vs all field values for one entity. |
| Primary key | Foreign key | Unique identifier in its own table vs link to another table. |
| Form | Report | Data entry/viewing interface vs formatted output/presentation. |
| Query | Report | Selects/retrieves records by criteria vs presents data in a designed layout. |
| Hierarchical model | Network model | Tree-like parent-child arrangement vs records can have multiple links. |
| CHAR | VARCHAR | Fixed-length text vs variable-length text; the storage/length behaviour differs. |
| Table | Database | A table stores records for one subject; a database may contain many related tables and other objects. |
C. Table-based questions
Q. A table BOOKS has BID, Name, DOP, Type and Price. Which field is the best primary key and why?
Answer: BID is the best choice if each book record has a distinct BID. It uniquely identifies each record, whereas names, types and prices may repeat.
Q. A table has 3 rows of data and 5 columns. How many records and fields does it contain?
Answer: It contains 3 records and 5 fields. The header row contains field names and is not counted as a data record.
Q. A table contains ItemID, Item Type, Quantity, Price and Supplier. Which fields may contain duplicate values?
Answer: Item Type, Quantity, Price and Supplier may contain duplicates. ItemID, when defined as the primary key, cannot contain duplicates.
Q. Can two rows have the same primary-key value? Explain.
Answer: No. A primary-key value must be unique. A duplicate would make it impossible to identify one record reliably.
Q. Can a table contain an image field?
Answer: Yes. The unit describes Binary data types as suitable for digitised images and sounds. In a Base table, select a suitable binary/image-capable field type supported by the installed version.
CHAPTER 9 - STARTING WITH LIBREOFFICE BASE
A. Data types
Q. What is a data type?
Answer: A data type specifies the kind of value that a field can store. Choosing a suitable data type helps store valid values and use storage efficiently.
Q. Differentiate between CHAR and VARCHAR. (PYQ pattern)
Answer: CHAR is fixed-length character data: the declared length is fixed. VARCHAR is variable-length text up to a specified maximum; storage depends on the characters entered. Use CHAR for fixed-format codes and VARCHAR for names/addresses.
Q. Which data type is suitable for a long description or notes?
Answer: Memo/LONGVARCHAR, because it is intended for longer text.
Q. Which data type is suitable for a student's date of birth?
Answer: Date.
Q. Which data type is suitable for a bill date and time in one field?
Answer: Timestamp, because it stores date and time information together.
Q. Which data type is suitable for a fee or price?
Answer: Currency for monetary values, or an appropriate numeric/decimal type if the task requires calculations and the database design specifies it.
Q. Which data type is suitable for a field that can have only Yes/No values?
Answer: Boolean, which stores two-state values such as True/False, Yes/No or On/Off.
Q. Which data type can store digitised images or sound data according to the unit?
Answer: Binary.
Q. Name examples of text data.
Answer: Names, addresses, PAN/card numbers and codes. Although a code may contain digits, it is often text if arithmetic calculations are not required.
Q. Name examples of numeric data.
Answer: Age, quantity, marks, price values and measurements that may need arithmetic calculations.
Q. What is the difference between Date, Time and Timestamp?
Answer: Date stores year/month/day; Time stores hour/minute/second; Timestamp stores date and time together.
B. Creating a database and tables
Q. What is LibreOffice Base?
Answer: LibreOffice Base is a free and open-source database application used to create and manage databases, tables, queries, forms and reports.
Q. What is the file extension of a LibreOffice Base database?
Answer: The database file is saved with the .odb extension.
Q. Write the basic steps to create a new database in Base.
Answer: Open LibreOffice Base; choose Create a new database; proceed through the Database Wizard; select the registration option as required (for a local practice database, choose not to register); finish; choose a folder and filename; save the database as an .odb file.
Q. How do you create a table using Design View?
Answer: Open the database and select Tables. Choose Create Table in Design View. Enter field names and choose data types; set field properties; identify a primary key; save the table with a suitable name; then enter records in the data view.
Q. What is the purpose of Design View when creating a table?
Answer: It lets the designer define field names, data types, field properties and the primary key before entering records.
Q. Why should data types be selected carefully?
Answer: They determine what values can be stored and how those values are handled. For example, a date field stores dates appropriately, while a numeric field supports calculations.
Q. Give suitable data types for Event_ID, Event_Name, Event_Date, Winner_Name and Winner_Points.
Answer: Event_ID: Text/VARCHAR if codes such as E001 are used; Event_Name: Text/VARCHAR; Event_Date: Date; Winner_Name: Text/VARCHAR; Winner_Points: Integer or another suitable numeric type.
Q. How can a table be edited or deleted?
Answer: In the table list, right-click the table and choose Edit to modify its design, or Delete to remove it. Confirm deletion carefully because the table and its data may be lost.
Q. What is the difference between table design and data view?
Answer: Table design defines the structure—field names, data types and properties. Data view displays records in rows and columns and is used to enter or edit values.
C. Common application/interface questions
Q. Name common objects shown in the Database pane.
Answer: Tables, Queries, Forms and Reports.
Q. Why is LibreOffice Base called a DBMS and not a spreadsheet?
Answer: It is designed to manage structured data in tables and support keys, relationships, queries, forms and reports. A spreadsheet primarily organises data in worksheets and performs calculations.
Q. Can a table's field be changed after records have been entered?
Answer: Yes, table design can be edited, but changes should be made carefully because changing/removing fields or data types can affect existing data.
Q. A school wants to store Event_ID values like E001 and E002. Should the field be numeric?
Answer: No. These are identifiers, not quantities for arithmetic. A text type is appropriate because the values contain letters and leading zeros may matter.
CHAPTER 10 - WORKING WITH MULTIPLE TABLES
A. Relationships and referential integrity
Q. Why are relationships created between tables?
Answer: Relationships connect related information, reduce unnecessary repetition, improve consistency and allow data from multiple tables to be used together.
Q. What is the most important prerequisite for creating a relationship between two tables? (PYQ pattern)
Answer: The tables must have a common field with compatible data types. Typically, the primary key of one table is linked to a matching foreign-key field in the related table.
Q. Must the common fields in related tables have the same data type?
Answer: Yes, they should have compatible/same data types for the relationship to be created correctly. A mismatch can prevent the relationship from being established.
Q. Name the three types of relationships between tables.
Answer: One-to-one, one-to-many and many-to-many.
Q. Explain a one-to-one relationship with an example.
Answer: Each record in Table A relates to at most one record in Table B and vice versa. Example: one person and one unique passport record.
Q. Explain a one-to-many relationship with an example.
Answer: One record in the first table can relate to many records in the second, while each record in the second table relates to one record in the first. Example: one customer can have many bills; each bill belongs to one customer.
Q. Explain a many-to-many relationship with an example. (PYQ pattern)
Answer: Many records in one table can relate to many records in another. Example: a student can enrol in many courses and each course can have many students. It is commonly implemented using a junction/bridge table, such as Student_Course.
Q. What is referential integrity? (PYQ pattern)
Answer: Referential integrity keeps relationships between tables valid. A foreign-key value must refer to an existing matching key in the related table (or be blank where allowed); it prevents orphan records and invalid links.
Q. A Bill table contains ItemID as a foreign key and Gadgets contains ItemID as primary key. Can a bill use an ItemID that does not exist in Gadgets?
Answer: No, if referential integrity is enforced. The Bill.ItemID must match an existing Gadgets.ItemID; otherwise the bill would refer to a non-existent product.
Q. Can a new record use an ItemID that already exists in Gadgets, where ItemID is the primary key?
Answer: No. Primary-key values must be unique, so a duplicate ItemID is not allowed.
Q. Give two advantages of relating tables. (PYQ pattern)
Answer: It reduces redundant data and prevents inconsistent copies of information. It also supports accurate retrieval of related information across tables.
Q. What happens if the same student's name changes in one related table?
Answer: A well-designed database stores the student's details in one main table and refers to that record from other tables. This reduces the need to repeat the name everywhere and reduces inconsistency. Update/delete behaviour depends on the relationship settings.
Q. What is a junction table?
Answer: A junction table connects two tables to implement a many-to-many relationship. It typically contains foreign keys referring to both related tables; their combination may be used as a composite primary key.
B. Scenario and table design
Q. A school has STUDENT (StudentID, Name, Class) and MARKS(MarksID, StudentID, Subject, Score). Identify the keys.
Answer: STUDENT.StudentID is the primary key. MARKS.MarksID is the primary key, and MARKS.StudentID is a foreign key referring to STUDENT.StudentID. If each student can have one row per subject, a composite key such as StudentID + Subject could also identify each marks entry if designed that way.
Q. A shop has GADGETS (ItemID, Item Type, Size, Quantity, Price, Supplier) and BILL(BillNo, ItemID, Price, CustName, CustPhoneNo). Identify the primary and foreign keys.
Answer: GADGETS.ItemID is the primary key. BILL.BillNo is the primary key. BILL.ItemID is a foreign key linked to GADGETS.ItemID.
Q. In the GADGETS table, name two fields where duplicate values are allowed.
Answer: Item Type and Supplier can repeat; Quantity and Price can also repeat. The primary-key field ItemID cannot repeat.
Q. A library table has BookID, BookName, Author, Price and Publisher. Which field should be primary key?
Answer: BookID, provided each book record has a unique BookID. BookName, Author, Price or Publisher may be repeated.
Q. If two tables have a common field but their data types differ, what should the database designer do?
Answer: Correct the table design so the linking fields have compatible data types, save the changes, and then create the relationship.
CHAPTER 11 - QUERIES IN BASE
A. Query fundamentals
Q. Why are queries used in a database?
Answer: Queries retrieve selected information from one or more tables using specified fields, sorting and search criteria. They save users from manually checking every record.
Q. In simple terms, what is a query?
Answer: A query is a question or request asked of a database.
Q. Can a query be saved and run again?
Answer: Yes. A query can be saved as a database object and run repeatedly whenever the latest matching data is needed.
Q. Name the ways to create a query in LibreOffice Base.
Answer: The unit and PYQ wording refer to Query Wizard, Design View and SQL view/SQL command. Some textbook activities describe two main visual methods—Wizard and Design View—so when a question asks for three ways, include SQL as the third.
Q. Which is the more flexible way to create a query?
Answer: Design View is more flexible because the user can directly choose fields, criteria, sorting, aliases and other settings in the design grid.
Q. Can a query use more than one table?
Answer: Yes. A query can retrieve data from one or more tables, especially when those tables are related appropriately.
Q. What does the query result look like?
Answer: Usually a datasheet-like table with fields displayed as columns and matching records as rows.
Q. What is a criterion in a query?
Answer: A criterion is a condition used to filter records, such as Marks > 50 or CategoryID = 'C001'.
Q. What is sorting in a query?
Answer: Sorting arranges query results in ascending or descending order based on a selected field.
Q. What is an alias in a query? (PYQ pattern)
Answer: An alias is an alternative display name for a field or column in the query result. For example, TotalFee may be displayed as 'Total Fee'.
Q. What is the purpose of the Visible check box in Query Design?
Answer: It controls whether a selected field appears in the query output. A field may be used for filtering or sorting without being displayed, if the Visible box is cleared.
Q. Can a query display the average or total of a numeric field?
Answer: Yes. Query functions can calculate aggregate values such as SUM, AVG, MIN, MAX and COUNT, depending on the query design and supported functions.
Q. What is the shortcut key to run a query as stated in the unit?
Answer: The textbook identifies F5 as the shortcut to run a query. In practice, shortcuts can vary by LibreOffice version and context, so follow the version installed in the lab if different.
Q. What is the purpose of the Alias row in the query design grid?
Answer: It lets the designer specify a more meaningful alternative column heading for the query result.
Q. What does the final/overview step of the Query Wizard show?
Answer: It shows the query's name and a summary/overview of the settings before finishing, allowing the user to review the query setup.
B. Query Wizard exam steps
Correct general sequence (wording may vary slightly by version):
- Open the database and select Queries → Use Wizard to Create Query.
- Choose the table or query as the data source.
- Move the required fields from Available Fields to Fields in the Query.
- Choose the required sorting order, if any.
- Set search conditions/criteria and choose whether all or any conditions must match.
- Choose detail or summary options if offered, and set aliases if required.
- Enter a query name; review the overview and finish.
- Open/run the saved query to view matching records.
Q. Rearrange these Query Wizard actions: set criterion; select fields; give table name; set sorting order; give alias.
Answer: First choose the table/data source; next select the fields; then set sorting; enter criteria; provide aliases where the wizard/version permits; finally name and save the query. The exact placement of alias options may vary by LibreOffice version.
C. Query design examples
Q. How would you retrieve students who scored more than 50 marks?
Answer: Create a query using the student/marks table, select the required display fields, and set the Marks criterion to > 50. Run the query to display only matching records.
Q. How would you display books from the 'Mystery' category in ascending order of price?
Answer: Select the required fields from BOOKS; set Type criterion to 'Mystery'; set Price sorting to Ascending; run the query.
Q. How would you show the total monthly rent collected for each room category?
Answer: Use a query based on the room/occupancy data; group records by Category and apply SUM to Monthly Rent. Ensure the source table/query includes the category and rent values to be totalled.
Q. How can a field be used for filtering but omitted from the result?
Answer: Add the field to the query design, enter its criterion, and clear its Visible check box so it is not shown in the output.
Q. What is the difference between a table and a query?
Answer: A table stores the underlying records. A query selects and displays records/fields according to criteria; it normally does not replace the source table.
CHAPTER 12 - FORMS AND REPORTS
A. Forms
Q. Why are forms needed when tables already exist?
Answer: Tables show data in rows and columns, which may be difficult for inexperienced users. Forms provide an easier, designed interface for entering, viewing and modifying data.
Q. What is a field control in a form?
Answer: It is a control associated with a field, usually including a label and a field-value box. The label tells the user what to enter; the input control accepts or displays the value.
Q. Name two ways to create a form in Base.
Answer: Use Wizard to Create Form or create the form in Design View.
Q. Give the general steps to create a form using the wizard.
Answer: Select Forms in the Database pane; choose Use Wizard to Create Form; choose the table/query and required fields; configure subform if needed; arrange controls; select data-entry mode and style; name the form; finish and test it.
Q. Name any two controls that may be used in a form. (PYQ pattern)
Answer: Text box and list box. Other examples include label, check box, radio button and combo box.
Q. How does a form help protect data quality?
Answer: It can present a structured interface with labels and suitable controls, reducing entry mistakes and making data entry easier. Validation still depends on field properties and database rules.
B. Reports
Q. What is the purpose of reports in a DBMS? (PYQ pattern)
Answer: Reports present selected database information in a formatted, organised and easy-to-read layout for viewing, printing or sharing.
Q. Can a report be generated from multiple tables?
Answer: Yes. A report can use data from multiple tables. A common method is to create a query combining the required tables first, then base the report on that query.
Q. What is a dynamic report? (PYQ pattern)
Answer: A dynamic report reflects changes in the underlying table/query data when it is refreshed or generated again. The exact update behaviour depends on how the report is opened and the data source.
Q. Differentiate between a form and a report.
Answer: A form is mainly an interactive interface for entering, viewing or modifying data. A report is mainly for presenting retrieved data in a formatted layout, often for printing.
Q. Can a report be based on a query?
Answer: Yes. A report can be based on a table, a query, or a suitable query that combines multiple tables.
Q. Why is it preferable to create a query before generating a report from multiple tables?
Answer: The query can join the necessary tables and select the required fields/records first. The report then presents this prepared result in a clear layout.
Q. How can current date/time be inserted into a report?
Answer: In the Report Builder/design environment, activate the appropriate header area and use the Insert menu's date/time field option; menu wording can differ by version. In an exam, name the Insert → Date and Time option if that matches the installed version/textbook menu.
Q. What are the two general ways to create a report in Base?
Answer: Using the Report Wizard or using the report/design environment, depending on the version and options available.
PYQ PATTERN BANK - 2025 AND 2026
This section collects the Unit 3 concepts identifiable in the shared 2025 and 2026 papers and adds equivalent rewordings. These are study questions based on the papers' concepts, not a claim that every sentence below is verbatim from a paper.
A. MCQs with answers
1. Q. A user wants a friendly screen for entering records. Which database object is suitable?
Answer: Form
2. Q. Which object presents information in a well-formatted, easy-to-read layout?
Answer: Report
3. Q. Which object is used to ask a database for selected records?
Answer: Query
4. Q. Which software is a free and open-source DBMS?
Answer: LibreOffice Base
5. Q. Which field uniquely identifies a row in a table?
Answer: Primary key
6. Q. Which object is not one of the core Base objects taught in this unit: Table, Query, Form, Report, Chart?
Answer: Chart
7. Q. Unnecessary repetition of data across tables is called what?
Answer: Data redundancy
8. Q. The values for all fields relating to one person/object make a what?
Answer: Record
9. Q. Which data type is appropriate for True/False values?
Answer: Boolean
10. Q. Which data type can store date and time together?
Answer: Timestamp
11. Q. Which relationship permits one customer to have multiple bills?
Answer: One-to-many
12. Q. What must be compatible in the linking fields when creating a relationship?
Answer: Data type
13. Q. Which query view is more flexible for detailed query design?
Answer: Design View
14. Q. What does an alias provide in a query?
Answer: An alternative field/column heading
15. Q. Which database object is mainly used for formatted print output?
Answer: Report
16. Q. Which data type from the unit is suitable for storing digitised images/sounds?
Answer: Binary
17. Q. Which key in the child table refers to the primary key in the parent table?
Answer: Foreign key
18. Q. Can a primary key contain duplicate values?
Answer: No
19. Q. Can the same supplier name occur in many product records?
Answer: Yes, unless that field is separately constrained to be unique
20. Q. Which model stores data in related rows-and-columns tables?
Answer: Relational data model
B. Short-answer PYQ-style questions
1. Q. State two features of the network data model.
Answer: Records can be linked through multiple connections rather than only a single tree hierarchy; a record may be associated with more than one other record, supporting complex relationships.
2. Q. Mention two prerequisites for setting relationships between tables.
Answer: The tables should have a common linking field, and the linking fields should have compatible data types. The parent table's key is commonly linked to a foreign key.
3. Q. Give two advantages of creating relationships between tables.
Answer: They reduce repeated data and help maintain consistency; they also let users retrieve related data across tables.
4. Q. Explain a many-to-many relationship with an example.
Answer: Students can study several subjects and each subject can be studied by many students. A Student_Subject junction table records the pairs.
5. Q. What is the purpose of a report? Can it use multiple tables?
Answer: A report formats data for clear presentation/printing. Yes; the report may use a query that combines multiple related tables.
6. Q. What is the difference between CHAR and VARCHAR?
Answer: CHAR stores fixed-length character values; VARCHAR stores variable-length values up to a specified maximum.
7. Q. What is a form? Name two controls.
Answer: A form is a user-friendly data-entry/view interface. Examples of controls: text box and list box.
8. Q. Explain referential integrity using Gadgets and Bill tables.
Answer: Gadgets.ItemID is the primary key and Bill.ItemID is a foreign key. A Bill record should refer to an existing Gadget item; an unknown ItemID should not be accepted when referential integrity is enforced.
9. Q. What happens if a duplicate primary-key value is entered?
Answer: The database rejects the duplicate because the primary key must uniquely identify each record.
10. Q. What is a dynamic report?
Answer: A report that can reflect the latest underlying data when refreshed or generated again.
C. Long/case-based PYQ-style answers
Q. Case 1- School database: A school stores students in STUDENT(StudentID, Name, Class) and marks in MARKS(MarksID, StudentID, Subject, Score). Identify the keys and explain the relationship.
Answer: STUDENT. StudentID is the primary key. MARKS.MarksID is the primary key and MARKS. StudentID is a foreign key referring to STUDENT.StudentID. One student can have several marks records, so the relationship is one-to-many. Referential integrity ensures every marks record refers to a valid student.
Q. Case 2-Gadget shop: GADGETS has ItemID, Item Type, Size, Quantity, Price and Supplier. BILL has BillNo, ItemID, Price, CustName and CustPhoneNo. (a) Which fields can repeat? (b) Can ItemID 1001 be entered twice? (c) What type stores product photos? (d) Explain referential integrity.
Answer: (a) Item Type, Size, Quantity, Price and Supplier may repeat. (b) No, because ItemID is the primary key and must be unique. (c) The unit identifies Binary as the type for digitised images/sounds; use an appropriate binary/image-capable type supported by the installed Base version. (d) Bill.ItemID must refer to an existing Gadgets.ItemID; this prevents billing records from linking to a non-existent product.
Q. Case 3- Boutique customer records: A boutique wants to maintain customer names, phone numbers, purchase details and billing dates in Base. Explain why a database is suitable, suggest field types, and describe a form.
Answer: A database stores related records in an organised way, supports fast retrieval and reduces redundant/inconsistent data. Customer name and phone number can use Text/VARCHAR; purchase amount can use Currency/Decimal; billing date can use Date, or Timestamp if date and time must be stored together. A form offers labelled fields and controls so staff can enter and view records easily.
Q. Case 4-Library query: The LIBRARY table contains BookID, BookName, Author, Category and Price. How can the librarian show only Mystery books in ascending price order?
Answer: Create a query using the LIBRARY table, add the fields to display, set Category criterion to 'Mystery', set Price sort order to Ascending, name and save the query, then run it. The result will show only Mystery books ordered from lowest to highest price.
Q. Case 5- Reports from several tables: The principal wants a printable report showing student name, class, book title and issue date from student and library tables. What should be done?
Answer: Create/confirm a relationship between the student and library/issue tables using a common key. Create a query that selects Student Name, Class, Book Title and Issue Date from the related tables. Then create a report based on that query and arrange the fields in a readable layout.
Q. Case 6- Relationship failure: Two tables have StudentID fields, but one is Text and the other is Integer. Why might the relationship fail and how should it be corrected?
Answer: The linking fields should have compatible data types. Make both fields compatible while preserving the actual identifier values, save the table designs, ensure the parent key is unique, then create the relationship and enforce referential integrity where appropriate.
D. True/False with corrections
1. Q. A primary key may contain duplicate values.
Answer: False – primary-key values must be unique.
2. Q. A form is mainly used to present a print-ready report.
Answer: False – a form is mainly for data entry/viewing: a report is for formatted presentation.
3. Q. A query can retrieve data from more than one table.
Answer: True.
4. Q. Data redundancy means data is repeated unnecessarily.
Answer: True.
5. Q. VARCHAR is intended for fixed-length text only.
Answer: False – CHAR is fixed-length; VARCHAR is variable-length.
6. Q. A foreign key can help create a relationship between tables.
Answer: True.
7. Q. A table field and a record mean the same thing.
Answer: False – field is a column/attribute; record is a row.
8. Q. A report may be based on a query.
Answer: True.
9. Q. Referential integrity allows a child record to refer to a non-existent parent key.
Answer: False – when enforced, the foreign key must refer to an existing key (or be null if allowed).
10. Q. LibreOffice Base is a spreadsheet application.
Answer: False – it is a database application/DBMS.
E. Fill in the blanks
1. Q. Raw facts are called ___________.
Answer: data
2. Q. Processed or organised data is called ___________.
Answer: information
3. Q. A field that uniquely identifies each record is a ___________ key.
Answer: primary
4. Q. A field used to link to a key in another table is a ___________ key.
Answer: foreign
5. Q. The values of all fields for one entity make a ___________.
Answer: record
6. Q. A user-friendly data-entry interface is a ___________.
Answer: form
7. Q. A question/request made to a database is a ___________.
Answer: query
8. Q. A formatted presentation of database data is a ___________.
Answer: report
9. Q. The LibreOffice Base database file extension is ___________.
Answer: .odb
10. Q. A data type for True/False values is ___________.
Answer: Boolean
11. Q. A data type storing date and time together is ___________.
Answer: Timestamp
12. Q. Unnecessary repetition of data is called data ___________.
Answer: redundancy
13. Q. A key made of two or more fields is a ___________ key.
Answer: composite
14. Q. An unused candidate key after selecting the primary key is an ___________ key.
Answer: alternate
15. Q. A many-to-many relationship is commonly implemented using a ___________ table.
Answer: junction/bridge
F. One-minute revision sheet
- Data = raw facts; Information = processed meaningful data.
- DBMS = software to create/manage/retrieve data; Base is a free and open-source DBMS.
- Database objects: Tables store; Queries retrieve; Forms support data entry/viewing; Reports format output.
- Field = column/attribute; Record = row; Table = records; Database = related data/tables.
- Primary key = unique, non-null identifier; Foreign key = link to another table; Candidate keys = all eligible unique identifiers; Alternate key = candidate key not selected as primary; Composite key = combination of fields.
- Relationship types: one-to-one, one-to-many, many-to-many. Check common field and compatible data type.
- Referential integrity prevents invalid foreign-key links/orphan records.
- Data types: CHAR fixed text; VARCHAR variable text; numeric for calculations; Currency for money; Date; Time; Timestamp; Boolean; Binary for image/sound; Memo/LONGVARCHAR for long text.
- Query criteria filter records; sorting orders records; alias changes a displayed heading; Design View is flexible; a saved query can be run again.
- Forms are for user-friendly entry/viewing. Reports are for formatted output. For multi-table reports, a query can combine the required tables first.
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