Having a problem setting up a composite key for names where some of the fields are blank. I can set it up for FirstName and LastName, but if I try to add a Middle Name (that may be blank) I can't get it to work.Read More...
Jim O
Reply from Alex Hedley:
How would that work if there was a null, the point is to create no duplicates among two or more fields.
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I want to be able to use two fields in combination to uniquely identify a record. For example, I want to have an Item Number and a Production Line in combination (i.e. Item Number "4060" and Production Line "Line 1" is a record; and Item Number "4060" and Production Line "Line 2" is a record. Is this possible?Read More...
Reply from Richard Rost:
Yep. That's what composite keys are for. More importantly, composite keys ensure that that COMBINATION of data is unique.
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Composite Keys : When or should you store calculated values in a database?
Reply from Richard Rost:
The ONLY time I recommend storing calculated values is when SPEED is an issue. If you have a complex calculation and you need to spit out long reports FAST, then it may make sense to store the calculated result, especially if it doesn't need to be recalculated frequently.Read More...
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