Database design and development
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what is the end-user requirements
the tasks the user needs to carry out
what is the functional requirments
The processes and activities that the database has to perform
what is a compound key
compound key is a key that has two or more primary/foreign keys from other tables
what is included in a data dictionary?
entity name key type required size validation
what is included in a query design?
fields tables search criteria grouping sort order
what wildcard symbol is used that matches one or more characters
• (asterisk)
what wildcard symbol is used that matches exactly one character
_ (underscore)
how is a sql update query structured
update set where
how is a sql insert into query structured
insert into values
how is a sql delete query structured
delete from where
what does MAX() aggregate function do?
finds the largest value of the selected column
what does MIN() aggregate function do?
finds the smallest value of the selected column
what does the SUM() aggregate function do?
returns the sum of a numerical column
what does the AVG() aggregate function do?
returns the average value of a numerical column
what does the COUNT() aggregate function do?
returns the number of rows that matched the specified criteria
how do you test sql queries?
produce a table of expected results, run the queries and check that the actual results match with the expected results
what does it mean by fitness for purpose?
it meets the end-user requirements and functional requirements
what does accuracy of output mean
the output is accurate if the expected results match the actual results