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Learn Primary Keys | Populating a Database
Introduction to SQL

bookPrimary Keys

A primary key is a column in a table which:

  1. Has a unique value for each row (no duplicate values);
  2. Cannot contain an empty / null value for any row.

A column can be marked as a primary key using the PRIMARY KEY keyword, inside the CREATE statement while creating the respective table.

Demonstration:

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SectionΒ 4. ChapterΒ 8

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bookPrimary Keys

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A primary key is a column in a table which:

  1. Has a unique value for each row (no duplicate values);
  2. Cannot contain an empty / null value for any row.

A column can be marked as a primary key using the PRIMARY KEY keyword, inside the CREATE statement while creating the respective table.

Demonstration:

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 4. ChapterΒ 8
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