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Methods of capturing, selecting, managing and exchanging data

Methods of capturing, selecting, managing and exchanging data.

1.3.2 Databases

Databases — Note 2 of 6

Candidates need to have an awareness of a range of methods for capturing data (such as forms, OCR, OMR and sensors) selecting data (such as Query By Example and SQL), managing data (such as changing data by manipulating it – e.g. arithmetic functions, adding, editing, deleting the data) and exchanging data (with commons formats such as CSV and JSON). Candidates won’t be specifically asked about any one of these methods but may be asked to discuss/justify suitable methods as part of a more open question. Candidates need to have an understanding of the need to interrogate data within a database. Candidates should understand the purpose of indexing in a database and the benefits of using indexing to optimise the searching for data. Candidates need to have experience of a range of methods for capturing data (such as forms – what do they collect, what do they look like - data mining, where does the data come from, how is it collected and analysed), selecting data (such as how to produce QBEs – adding fields, tables, criteria, sorting - selecting through Boolean expressions – AND, OR, NOT), managing data (such as changing data by manipulating it – e.g. arithmetic functions - , adding, editing, deleting the data) and exchanging data (such as methods of transferring data – electronic i.e. memory stick, e-mail, and non-electronic e.g. paper based - appropriate formats for the transfer of data and communication mediums to transfer data – such as the structure, is it in a table or a list).

What you need to know

Data must be captured, selected, managed and exchanged efficiently and accurately. You will not be asked about one method in isolation, but you may need to discuss and justify suitable methods for a scenario.

What to know

  • Capturing data: paper or online forms, OCR (optical character recognition), OMR (optical mark recognition, e.g. multiple choice answer sheets), barcodes and QR codes, RFID, sensors, and data logging.
  • Automated capture (e.g. sensors, barcodes) is faster and reduces human input errors; manual forms are flexible but slower and error-prone.
  • Selecting data: Query By Example (QBE), where fields, tables, criteria and sort order are chosen in a visual grid, and SQL, where queries are written as text.
  • Managing data: a DBMS (database management system) is used to add, edit and delete data, carry out calculations, enforce validation and control access.
  • Exchanging data: common formats such as CSV (comma-separated values) and JSON (JavaScript Object Notation) allow data to be moved between different systems. Data can also be exchanged electronically (e-mail, network, removable media) or on paper.
  • Validation (e.g. range, type, presence, format checks) and verification (e.g. double entry, visual check) help ensure the data captured is accurate.

Exam technique

  • Tip:Justify methods in context, e.g. 'OMR is suitable for marking 1,000 multiple-choice papers because it is fast and avoids human marking errors.'

Code examples

The same record exchanged as CSV and as JSON
text
CSV:
StudentID,Name,Year
1042,Sam Patel,12

JSON:
{ "StudentID": 1042, "Name": "Sam Patel", "Year": 12 }

Databases

Note 2 of 6

  1. 1Relational databases, flat files, keys, entity relationship modelling, normalisation and indexing
  2. 2Methods of capturing, selecting, managing and exchanging data
  3. 3Normalisation to 3NF
  4. 4SQL: interpret and modify
  5. 5Referential integrity
  6. 6Transaction processing, ACID, record locking and redundancy
Topic overview
← Previous noteRelational databases, flat files, keys, entity relationship modelling, normalisation and indexing1.3.2 DatabasesNext note →Normalisation to 3NF1.3.2 Databases

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