what is primary key?

rajmanisha

rajmanisha

@rajmanisha-XaHpQ5 • Oct 27, 2024
what is primary key?
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  • Kaustubh Katdare

    Kaustubh Katdare

    @thebigk • Jul 9, 2017

    rajmanisha
    what is primary key?
    How about adding a little more reference to your question? Are we talking about databases here?
    0
  • Neeraj Sharma

    Neeraj Sharma

    @neeraj-iAaNcG • Jul 9, 2017

    rajmanisha
    what is primary key?
    #-Link-Snipped-#
    0
  • Shweta Chauhan

    Shweta Chauhan

    @shweta-pzk2Ut • Jul 10, 2017

    In context of DBMS, primary key is a column in a table that uniquely identifies the rows of that table.Several rows of a table can have similar value for a column but in case if that column is a primary key for that table, it can't be same.
    In addition to uniquely identifying a row, it also ensures that there cannot be any null value in that column(if it is the primary key for that table)
    A simple example:
    upload_2017-7-11_16-13-27
    Here Roll No. column is the primary key of this table so values in that column cannot be same,but name and marks can have similar values.
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  • vinod12345madhu

    vinod12345madhu

    @vinod12345madhu-FwUje1 • Aug 14, 2017

    rajmanisha
    what is primary key?
    your aadhar number (Social security number ) in the US, Driving license number etc all can be your your primary key.
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