Once students understand databases and table structure, the next essential step in IB Computer Science is learning SQL. SQL is not about programming logic or algorithms — it is about asking precise questions of data.
IB examiners expect students to understand what SQL is, why it is used, and how it interacts with databases, even before writing complex queries.
What Is SQL?
SQL (Structured Query Language) is a standard language used to:
- Access data stored in databases
- Retrieve specific information
- Insert, update, and delete records
SQL is used with relational databases, where data is stored in tables made up of records and fields.
In IB Computer Science, SQL is treated as a data query language, not a general-purpose programming language.
Why SQL Is Used
Databases may store millions of records. SQL allows users to:
- Retrieve only the data they need
- Filter results
- Sort information
- Combine data from multiple tables
Without SQL, users would need to search data manually, which is impractical and inefficient.
IB exam questions often focus on SQL’s role in efficient data access.
How SQL Works with a Database
SQL works by sending queries to a database.
The process is:
- A query is written using SQL
- The database management system interprets the query
- The database searches the relevant tables
- The results are returned
Users do not interact directly with raw data — the DBMS handles all data access.
Common SQL Operations in IB Computer Science
IB students are expected to recognise four main categories of SQL operations:
- SELECT – retrieve data
- INSERT – add new records
- UPDATE – modify existing records
- DELETE – remove records
These operations are often referred to as CRUD:
- Create
- Read
- Update
- Delete
Understanding CRUD is more important than memorising syntax early on.
Tables, Fields, and Records in SQL
SQL queries refer directly to:
- Tables – collections of related data
- Fields – individual attributes (columns)
- Records – individual entries (rows)
For example:
- A table stores student data
- Each record represents one student
- Each field stores one piece of information
IB examiners expect students to use these terms correctly.
SQL and Database Design
SQL depends on good database design.
Well-designed databases:
- Make SQL queries simpler
- Reduce errors
- Return accurate results
Poorly designed databases:
- Require complex queries
- Increase the risk of incorrect data
- Reduce efficiency
This is why SQL is taught after database structure and normalisation.
What IB Students Are Expected to Do with SQL
In IB Computer Science, students may be asked to:
- Write simple SQL queries
- Interpret existing queries
- Explain what a query does
- Modify queries to meet requirements
Students are assessed on understanding, not just memorisation.
Common Student Mistakes
Students often:
- Treat SQL like a programming language
- Forget that SQL works on tables
- Confuse records and fields
- Write vague explanations of queries
Precision in language and logic is essential.
How SQL Appears in IB Exams
SQL questions may involve:
- Selecting specific data
- Filtering records
- Sorting results
- Linking tables conceptually
Clear explanations of intent earn higher marks than perfect syntax alone.
Final Thoughts
SQL is the language that allows users to interact meaningfully with databases. It turns stored data into useful information by allowing precise, efficient queries.
Understanding what SQL is and why it is used gives IB Computer Science students a strong foundation for writing queries, analysing data, and understanding real-world information systems.
