Data, Databases and Emerging Technologies
Data, Databases and Emerging Technologies covers how data becomes useful information, how relational databases are structured and queried, and what current technologies do. Expect definitions, key identification, simple SQL, and balanced explanations of benefits and risks.
Core rules and concepts
- Data are raw facts; information is processed data with meaning. Validation checks whether input is reasonable (for example, a range check); verification checks that data was copied or entered accurately.
- A relational database stores data in tables made of records (rows) and fields (columns). A primary key uniquely identifies each record; a foreign key links to a primary key in another table.
- A DBMS lets users create, update, query, and secure data, and helps control redundancy and integrity.
- SQL: SELECT chooses columns, FROM names the table, WHERE filters rows, and ORDER BY sorts results.
- Emerging technologies include AI, cloud computing, IoT, and blockchain. Learn a specific use, a benefit, and a limitation for each.
Worked example
Table Student(StudentID, Name, Year). List the names of Year 11 students alphabetically: SELECT Name FROM Student WHERE Year = 11 ORDER BY Name; Reasoning: SELECT Name returns only the requested column; WHERE filters records to Year 11; ORDER BY Name sorts the output. Numeric values are not quoted, while text values need quotes.
Traps
- Running DELETE or UPDATE without WHERE, which affects every record.
- Quoting numbers or failing to quote text in SQL.
- Confusing a primary key (unique identifier) with a foreign key (a link to another table).
- Treating validation as proof of accuracy; validation only checks acceptability.
- Describing emerging technologies only as “good” or “bad” without a concrete use, benefit, or risk.