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Help understanding ER diagram

Data Science for Small Business Applications › Forums › SQL › Help understanding ER diagram

Tagged: ER diagram, infinity symbol in ER diagram, primary key in SQL

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  • April 16, 2022 at 5:32 am #118
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      SQL https://www.coursera.org/learn/sql-for-data-science

      An explanation of why few tables are kept black as well how to make sense of primary key and infinity symbol appreciated.


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      It appears that some entities are blacked out because they really do not matter for the question being asked.

      The primary key symbol identifies the column(s) that make up the primary key.

      The infinity symbol identifies one-to-many relationships.

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