Reputation: 199

What does nullable signify for a database

What is nullable refers for a Database, and what does it signifies ?
nullable = 0
nullable = 1

The Image contains column value of a table where nullable is defined:

Note : Check the highlighted value in Picture

Upvotes: 4

Answers (4)

Reputation: 96

Nullable field (marked with 1) is allowed to have NULL values. If it is marked with 0, it means that it must have a value inside.

Upvotes: 7

Reputation: 1

It's an additional flag for a database column type which signifies whether or not that column can be set to NULL.

Upvotes: 0

Reputation: 162

It's a boolean flag to tell if the columns is nullable (aka it can contains null).

If nullable = 1 the column can contains null.

Upvotes: 0

Reputation: 219

Nullable means it can have a null value, thus not required.

Upvotes: 2