Can 0 be a primary key?

Question

Primary Key Can be Zero, but if you set Identity on the column it normally will start at 1 rather than Zero. Primary Key will have Identity Column .. 25 мар. 2011 г.

Can primary key be 0 MySQL?

Specifically, if you use 0 in an INSERT for a primary key, MySQL interprets that as a request to generate a new key. Again, day to day, there won't be any problems running Magento with these rows, since the 0 ID already exists. However, if you need to move or upgrade the data you might run into a problem.

Can a primary key have no value?

A primary key is a field in a table which uniquely identifies each row/record in a database table. Primary keys must contain unique values. A primary key column cannot have NULL values. A table can have only one primary key, which may consist of single or multiple fields.

Can primary key be empty string?

Columns with empty strings can be used in primary keys and as foreign keys without a problem.

Can a primary key be anything?

A primary key is not a special type of key. It is one of the keys of a table. If a table has only one key then a choice of primary key does not arise.

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