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Computer Science Step 2: Executing the query (b) Data accuracy: Utilizes primary and
foreign keys to relate tables, reducing
Use a DBMS software to
data duplication and enhancing
execute the SQL query on
accuracy.
the “emp” table or relevant
(c) Easy data access: No fixed pattern
dataset. Retrieve and record
FOR ONLINE READING ONLY
the results that match the
any table or combination of tables
criteria “deptno=30”. for accessing data; users can query
effortlessly.
Step 3: Formatting results (d) Data integrity: Ensures robust data
Present the query results entry and validation, maintaining
in a tabular format similar relational reliability and preventing
to Figure 8.13. Include isolated or unrelated records.
columns for “Fname”, (e) Flexibility: Can scale and adapt to
“job”, “hiredate”, and “sal”, changing needs with no limits on
with each row representing rows, columns, or tables, allowing
an employee meeting the efficient updates and deletions.
selection criteria. (f) Normalisation: Ensures database
structure integrity by eliminating
Deliverable: variances and achieving
Submit a comprehensive documentation normalization, typically up to the
of the process and results in your report third normal form.
or portfolio. Include a brief analysis of (g) High Security: Allows selective
the selected dataset, highlighting any confidentiality for tables, restricting
observations or insights gained from access based on user roles.
the exercise. Present the query results (h) Future modifications: Easily
in a structured table format similar to accommodates new requirements,
Figure 8.13, demonstrating proficiency allowing straightforward insertion,
in selection and projection operations deletion, or updating of records.
within a database context.
Examples of relational database
Advantages of relational database systems
model Relational database systems are used
A relational database system has multiple in many organisations today. There are
advantages, as described in the next several common and popular relational
paragraphs. database systems based on: end-users,
(a) Simple model: Easy to structure and open source, and proprietary, as follows:
query without complex processes, (a) Popular DBMSs for end-users: The
unlike hierarchical and network popular and most used relational
models.
450
for Advanced Secondary Schools
Computer Science Form 5.indd 450 23/07/2024 12:34
