Can you have multiple primary keys?

Question

You can only have one primary key, but you can have multiple columns in your primary key. You can also have Unique Indexes on your table, which will work a bit like a primary key in that they will enforce unique values, and will speed up querying of those values. 20 окт. 2008 г.

Can there be 2 primary keys?

A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).

Can you have several primary keys?

It is possible for a table to have multiple candidate keys , which effectively behave similar to a primary key in that a candidate key is unique, NOT NULL , and is a singular representation of that table record.

Can you have 3 primary keys?

A table can only ever have a one primary key. It is not possible to create a table with two different primary keys. You can create a table with two different unique indexes (which are much like a primary key) but only one primary key can exist.

How many primary keys can have in a?

A table's primary key should be explicitly defined in the CREATE TABLE statement. Tables can only have one primary key.

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