What kind of data should be used for a primary key?

Data Type. Integer (number) data types are the best choice for primary key, followed by fixed-length character data types.

Why SSN should not be made a primary key?

Social Security numbers do not make good primary keys for many reasons. Most people consider their SSN private and do not want it clearly visible to database users. In addition, some people don’t have SSNs. Email addresses are also a poor choice for a primary key.

Can we make phone number as primary key yes or no give reason?

2 Answers. As noted above, you technically could use a phone number as a primary key, but it is not a best practice, because: You would not be able to insert another user who happens to have the same phone number (primary keys must be unique).

Is ID column necessary?

8 Answers. If you really do have some pre-existing column in your data set that already does uniquely identify your row – then no, there’s no need for an extra ID column. The primary key however must be unique (in ALL circumstances) and cannot be empty (must be NOT NULL).

Should I use int as primary key?

Guid vs INT – Which is better as a primary key? – Database Administrators Stack Exchange.

How do you describe a primary key?

A primary key, also called a primary keyword, is a key in a relational database that is unique for each record. It is a unique identifier, such as a driver license number, telephone number (including area code), or vehicle identification number (VIN). A relational database must always have one and only one primary key.

What considerations might influence the choice of a primary key?

The criteria for consideration of a primary key are:

• Uniqueness.
• Irreducibility (no subset of the key uniquely identifies a row in the table)
• Simplicity (so that relational representation & manipulation can be simpler)
• Stability (should not be altered frequently)
• Familiarity (meaningful to the user)

Is it bad practice to use email as primary key?

Not really. For any sizable data set, you’ll end up wasting a lot of space and you’ll take a performance hit when querying. In addition, if someone changes their e-mail (which you might or might not allow), you’ve got to change it everywhere. A surrogate key to uniquely identify the user would be a much better choice.

Can email be used as a primary key?

Yes, it is a bad primary key because your users will want to update their email addresses. yes, it is better if you use an integer instead. you can also set your email column as unique constraint.