9-3-2 Database design
When designing a database, it is necessary to consider points such as “data
analysis”, “data design”, and “data normalization.”
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Data analysis
Before creating a database, it is important to clarify what kind of task will
be converted into database format, and what it will be used for. In order to
design tables in a logical manner, printing results that correspond to the
purpose, and the input items necessary to obtain those results are determined.
Determine what printing results are ultimately required
and choose the input items accordingly.
Table design
Design the tables based on the selected input items.
Link the tables with common items and have them
reference the data as necessary. Categorizing the
input items and dividing the tables enable the
construction of a database that prevents redundant
data entry, unnecessary disk usage, and input error.
Data is normalized to design the table.
Technology element
Determining printing
results and input items
Chapter 9
Clarification of purpose
Analyze the flow of work and clarify the purpose of the
database such as sales or inventory control. Clarify
details such as how the database will be used and by
whom.
The key points in table design are summarized below.
• Eliminate repetitive data.
• Ensure that data is only registered once.
• Do not save data obtained through calculation in the tables.
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