What is a Primary Value ?
- 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.
- It should be usually associated with a column which is uniquely identifiable. However, this uniqueness is not enforced at the database level.
What is the use of Primary Value ?
- Within a spreadsheet, primary value are always highlighted so that it is easier to recognise what row we are in.
- And when LinkToAnotherRecord is created between two tables - it is the primary value that appears in LinkToAnotheRecord column.
Example : Primary Value highlighted in Actor table
Example : Primary Value highlighted in Film table
Example : Primary Value associated when LinkToAnotherRecord is created
How to set Primary Value ?
Click down arrow in the target column. Click
Set as Primary Value.
How is Primary Value identfied for existing database tables ?
- It is usually the first column after the primary key which is not a number.
- If there is no column which is not a number then the column adjacent to primary key is chosen.
Can I change the Primary Value to another column within tables ?
- Yes, you can use the same way mentioned above to set Primary Value.