Curriculum
Grade XII Computer Science
Lessons
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Ch-1 Exception Handling in Python
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Ch-2 File Handling in Python
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Ch-3 Stack
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Ch-4 Queue
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Ch-5 Sorting
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Ch-6 Searching
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Ch-7 Database Concepts
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Ch-8 Structured Query Language (SQL)
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Ch-9 Computer Networks
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Ch-10 Python-SQL Connectivity
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Ch-7 Database Concepts
School Revise · Class 11 Computer Science · Chapter 7
Database Concepts
Code 083, Class 12. A database stores data in tables so it is easy to keep and find. Here we meet the relational model and its keys.
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What this chapter is about
A database is an organised store of data. A DBMS (Database Management System) is the software that manages it. In the relational model, data is kept in tables.
1. Tables, rows and columns
A relation is a table. A tuple is a row (one record). An attribute is a column (one field). The number of columns is the degree and the number of rows is the cardinality.
2. Keys
A primary key is a column whose value is unique for each row and identifies it. A candidate key can serve as a primary key. An alternate key is a candidate key not chosen as the primary key. A foreign key links to the primary key of another table.
3. Why use a database
A DBMS reduces repeated data, keeps data consistent and secure, and lets many users share it, which a simple file cannot do well.
Practise with the interactive
Explore the idea by tapping. The interactive opens right here in the lesson.
Practice set A, multiple choice
1. A row of a table is called a …
tuple.
2. A column of a table is called an …
attribute.
3. Which key uniquely identifies each row?
The primary key.
4. The number of rows is the …
cardinality.
Practice set B, short answer
1. What is a DBMS?
Software that stores and manages a database.
2. Define degree and cardinality.
Degree is the number of columns; cardinality is the number of rows.
3. What is a foreign key?
A column that links to the primary key of another table.
Quick summary
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A database is an organised store of data, managed by a DBMS. In the relational model, data is in tables (relations); a row is a tuple, a column is an attribute. Degree is the number of columns, cardinality the number of rows. A primary key identifies each row, and a foreign key links tables. A DBMS reduces repetition and keeps data consistent, secure and shareable. |
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These free Class 12 Computer Science notes explain database concepts, the relational model, tuples and attributes, degree and cardinality, and primary candidate alternate and foreign keys with worked examples and practice, for CBSE students across India and the Gulf including the UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain.
© 2026 School Revise. All rights reserved. Original content aligned to the CBSE and NCERT Class 12 Computer Science syllabus. Unauthorised copying is not permitted.
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