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@ -10,11 +10,20 @@ menuTitle: "Primary value" |
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- Primary value as the name stands is the primary or main value within a row of a table that you generally associate that row with. |
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- Primary value as the name stands is the primary or main value within a row of a table that you generally associate that row with. |
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- It should be usually associated with a column which is uniquely identifiable. However, this uniqueness is not enforced at the database level. |
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- It should be usually associated with a column which is uniquely identifiable. However, this uniqueness is not enforced at the database level. |
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## What is the use of 'Primary value' ? |
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## What is the use of 'Primary value' ? |
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- Within a spreadsheet, primary value are always highlighted so that it is easier to recognise what row we are in. |
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- Within a spreadsheet, primary value are always highlighted so that it is easier to recognise what row we are in. |
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- And when LinkToAnotherRecord is created between two tables - it is the primary value that appears in LinkToAnotheRecord column. |
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- And when LinkToAnotherRecord is created between two tables - it is the primary value that appears in LinkToAnotheRecord column. |
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#### Example : ```Primary value```highlighted in actor table |
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<img width="547" alt="actor" src="https://user-images.githubusercontent.com/5435402/152645708-92b83985-4a0a-42b2-9d01-d26be70fd3aa.png"> |
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#### Example : ```Primary value``` highlighted in film table |
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<img width="1406" alt="film-table" src="https://user-images.githubusercontent.com/5435402/152645713-b4df99b2-4eb7-4fea-85f9-0baf47470ef3.png"> |
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#### Example : ```Primary value``` associated when ```LinkToAnotherRecord``` is created |
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<img width="753" alt="actor-film" src="https://user-images.githubusercontent.com/5435402/152645714-4061c94a-4cfb-44e5-b112-63cf4ed869fe.png"> |
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## How is ```Primary value``` identfied for existing database tables ? |
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## How is ```Primary value``` identfied for existing database tables ? |
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- It is usually the first column after the primary key which is not a number. |
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- It is usually the first column after the primary key which is not a number. |
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- If there is no column which is not a number then the column adjacent to primary key is chosen. |
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- If there is no column which is not a number then the column adjacent to primary key is chosen. |
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