1
Q
Database
A
a collection of organized data stored in a structured and logical way which can be retrieved using queries
2
Q
Primary key
A
a field where every valued stored is unique
3
Q
validation
A
process of examining input so only reasonable data is accepted
4
Q
data types in SQL?
A
- Text/Alphanumeric (letters + numbers etc.)
- Character (single letters/symbols)
- Boolean (true or false)
- Integer (whole numbers; +ve & -ve)
- Real (decimal points included)
- Date/Time
5
Q
Layout of SQL
A
SELECT… <fields> - SUM() & COUNT()
FROM <tablename>
WHERE <condition>
ORDER BY... ASCENDING/DESCENDING</condition></tablename></fields>
6
Q
what does * do in SQL
A
all columns or all rows or replaces any character
7
Q
sum() and count() function and when to use
A
sum() - returns total sum of a numeric column and only in numeric fields
count() - returns a single value and counts (for any field)
