What is primary key in database?

By Arsal Ahmed   Posted on March-20-2018 

What is primary key in database?

A primary key is a special relational database column or combinations of columns designed to uniquely identify all the table records.

  • It must contain a unique value for each row of data
  • It cannot contain null values.
  • The primary key is inserted in the first column in which it is inserted with the name that had an ID name in column.
  • The null value will not show in the column of table.

A primary key is a special relational database column or combinations of columns designed to uniquely identify all the table records.

  • It must contain a unique value for each row of data
  • It cannot contain null values.
  • The primary key is inserted in the first column in which it is inserted with the name that had an ID name in column.
  • The null value will not show in the column of table.

By Arsal Ahmed    20-Mar-2018 



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