Sunday, 15 June 2014

mysql - Compound key/ Composite Key / Concatenated Key / Aggregate Key / Candidate Key -


Can anyone give me a clear idea of ​​the difference between these keys?

  • Total key
  • Integrated key
  • Total key
  • Candidate key

    I searched for all these explanations and it seems that some of them are just synonyms but it is not certain if I understood correctly, I would be grateful if any difference and Compared with similarity, a descriptive answer may come along.

    The database word in the relational is only a key type of key: an candidate key .

    A candidate key is a set of specific properties that, in a table, irrelevant unique and non- unimpressed means that all of the key Attributes are required - Delete any one attribute and property of specificity will be lost. A key should contain at least one key from zero, one or more characteristics, and relational table (relation variables) and can be more than one.

    Complex , holistic , concatenated and total Specialty is used to describe the candidate's key. With a specialty, a candidate key is called the Simple key

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