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Question about keys RRS feed

  • Question

  • User954998566 posted

    Hi, I'm trying to complete these keys. 

    Primary Key

    Unique Key

    Thanks

    Monday, August 1, 2016 5:21 PM

Answers

  • User-359936451 posted

    you are missing 2 other key words, Index and foreign.

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Monday, August 1, 2016 8:40 PM
  • User-1404113929 posted

    hi,

    clustered index  and foreign key

    thanks,

    murali

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Tuesday, August 2, 2016 7:09 AM

All replies

  • User-359936451 posted

    you are missing 2 other key words, Index and foreign.

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Monday, August 1, 2016 8:40 PM
  • User-1404113929 posted

    hi,

    clustered index  and foreign key

    thanks,

    murali

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Tuesday, August 2, 2016 7:09 AM
  • User-2057865890 posted

    Hi Salim,

    Following is the list of Keys.
    1. Super Key
    Super key is a set of one or more than one keys that can be used to identify a record uniquely in a table. Example : Primary key, Unique key, Alternate key are subset of Super Keys.
    2. Candidate Key
    A Candidate Key is a set of one or more fields/columns that can identify a record uniquely in a table. There can be multiple Candidate Keys in one table. Each Candidate Key can work as Primary Key.
    3. Primary Key
    Primary key is a set of one or more fields/columns of a table that uniquely identify a record in database table. It can not accept null, duplicate values. Only one Candidate Key can be Primary Key.
    4. Alternate key
    A Alternate key is a key that can be work as a primary key. Basically it is a candidate key that currently is not primary key.
    5. Composite/Compound Key
    Composite Key is a combination of more than one fields/columns of a table. It can be a Candidate key, Primary key.
    6. Unique Key
    Uniquekey is a set of one or more fields/columns of a table that uniquely identify a record in database table. It is like Primary key but it can accept only one null value and it can not have duplicate values.
    7. Foreign Key
    Foreign Key is a field in database table that is Primary key in another table. It can accept multiple null, duplicate values.

    Regards

    Chris

    Thursday, August 4, 2016 2:23 PM