VCE Data Analytics U3O1 Definitions Worksheet: Data types and relational databases to Sourcing, validating and referencing data (Modules 17–49)
Name:
Date:
Class:
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Key terms
Write what each term means, in your own words.
1
VARCHAR(30)
2
VARCHAR(50)
3
one-to-many relationship
4
AND, OR, NOT
5
Export query results as CSV
6
authentic data
7
file format
8
ISBLANK
9
ISNUMBER
10
=AND(B2>=0,B2<=100)
Answer Key
VCE Data Analytics U3O1 · Modules 17–49 · Student wording will vary for definitions
1VARCHAR(30) — Field size sets the maximum length or storage a value may use. VARCHAR(30) allows up to 30 characters; longer values are rejected or cut. Smaller sizes save storage.
2VARCHAR(50) — A column's data type and size set in CREATE TABLE. VARCHAR(50) holds text up to 50 characters. Other types: INT, DECIMAL(8,2), DATE, BOOLEAN. They control what a column stores.
3one-to-many relationship — One record in a primary table matches many records in a related table. The foreign key sits on the many side, e.g. one class has many students, so class details are not repeated.
4AND, OR, NOT — Combine WHERE conditions: AND needs both true, OR needs at least one true, NOT reverses a condition. Brackets set the order and decide which rows are returned.
5Export query results as CSV — Save the rows a query returns as a CSV file with a header row of field names. Import it into a spreadsheet, then check the columns came across correctly before further analysis.
6authentic data — Real data collected by a trusted organisation and kept in a large repository; check its publisher, date and relevance to your question.
7file format — The way a dataset's data is structured and stored in a file, such as CSV, XLSX, JSON or XML. Choose the format that suits the software you will open it in.
8ISBLANK — A spreadsheet function that checks a cell. It returns TRUE if the cell is empty and FALSE if it holds data, so it works as an existence check. COUNTBLANK counts empty cells in a range.
9ISNUMBER — A function that tests whether a cell value is a number. It returns TRUE for a number and FALSE for text, so it works as a type check. ISTEXT does the same job for text.
10=AND(B2>=0,B2<=100) — A range check formula. It returns TRUE only if the value in B2 is at least the minimum (0) and at most the maximum (100), so boundary values pass and anything outside is rejected.