This is personal study note
Copyright and original reference:
https://www.youtube.com/watch?v=hGVdzWstuqc&list=PLuHgQVnccGMDF6rHsY9qMuJMd295Yk4sa
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create "write" table
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create relationship
author to write (1:N)
topic to write (1:N)
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author : write (N)
author : write (optional)
write : author (1)
write : author (mandatory)
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