Questions

A primary key is a special relational database table column or combination of columns designated to uniquely identify all table records. That is, A primary key is a column or set of columns in a table that uniquely identifies tuples (rows) in that table.

A primary key, also called a Primary Keyword.

Main Features Primary key are ::

It must contain a unique value for each row of data.

It cannot contain null values.

The brand ambassador of the Swast Immunised India campaign is Kareena Kapoor Khan.

Violet colour has the highest energy. The higher the frequency, the faster the oscillations and thus the higher the energy. Therefore, the highest-frequency ultra-violet light or the lowest wavelength is violet.