We've been getting a number of this type of question lately: short, and simple on the surface. Short questions...
are wonderful, because they leave more room for the answer. Simple questions are even better, as long as they aren't too simple.
In this case, it's a good question but it might have been too simple.
A candidate key is any key that could be used as the primary key. This comes with two requirements: it cannot be null, and its values must be unique.
A composite key contains more than one column.
Dig Deeper on Oracle and SQL
Related Q&A from Rudy Limeback
Read an example of an SQL case expression from our SQL expert Rudy Limeback. Continue Reading
Read SQL expert Rudy Limeback's advice for counting combinations in a table with SQL's GROUP BY clause Continue Reading
Read about the Mimer Validator, a tool used to verify your SQL code, in this tip from SQL expert Rudy Limeback. Continue Reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.