JSS 3 First Term

Lesson objectives

By the end of the week, learners should be able to:

1. Define a database system and describe its role in organisations.
2. Name the main components of a relational schema.
3. Write basic SQL CREATE TABLE statements for fields and constraints.
4. Describe a primary key and a foreign key and their roles.
5. Judge whether a schema satisfies business rules.

Key vocabulary

• Database system: software storing, managing and retrieving records.
• Schema: the design defining tables, fields and relationships.
• Relational schema: a tabular schema holding linked tables.
• CREATE TABLE: SQL syntax declaring a new table.
• Field: a column holding a characteristic of each record.
• Constraint: a rule limiting allowed data values.
• Primary key: a unique identifier for each record within a table.
• Foreign key: a field linking a row in one table to another.
• Business rule: an operational requirement a schema must satisfy.

Common misconceptions

• "A database is just a spreadsheet." Databases enforce constraints and relationships that spreadsheets ignore.
• "SQL creates empty tables only." SQL can insert data and define relationships too.
• "Primary keys can share values." Primary keys must uniquely identify each record.

Teacher activities

1. Starter: ask where a school keeps student records if not on a teacher's desktop.
2. Define a database system and describe its organisational role.
3. Name the main relational schema components one by one.
4. Demonstrate writing a CREATE TABLE statement with constraints.
5. Define primary and foreign keys with a worked example.
6. Close with the schema-satisfies-rule task and exit question.

Student activities

1. Answer the starter and identify the right storage location.
2. Define a database system in their own words and state its role.
3. Name the main relational schema components in one sentence each.
4. Write a CREATE TABLE statement with fields and constraints.
5. Define a primary key and a foreign key with one example each.
6. Judge whether a given schema satisfies the stated business rules.
7. Answer the exit question in one sentence about databases versus spreadsheets.

Practical / learning evidence

A CREATE TABLE worksheet, a primary-key-versus-foreign-key example and a schema-satisfies-rule worksheet. Submit all three for marking.

Resources and preparation

Printed SQL templates, blank schema diagrams and sample business rules. Offline route: paper versions, no device needed. Display any DBMS installation carefully and avoid touching live databases.

Assessment for learning

Inspect the CREATE TABLE for correct syntax and constraint names. Check the PK versus FK example for correct links. Mark the schema-satisfies-rule for defensible judgement. Flag any learner who calls the database a big spreadsheet.

Inclusion and homework

Provide the CREATE TABLE prefilled for field and constraint names and allow oral SQL. Extend confident learners with two CREATE TABLE statements and a third homework to verify foreign-key integrity. Homework: name one advantage and one disadvantage of relational databases over spreadsheets.