Is it bad to use string as primary key?

Is it bad to use string as primary key?

The short answer : It’s perfectly fine to use a string as a primary key. What is a good primary key candidate ? It should be unique. It should rarely, if at all, change.

Should it be string or int?

5 Answers. You are doing the right thing – identity field should be numeric and not string based, both for space saving and for performance reasons (matching keys on strings is slower than matching on integers).

Should primary keys be integers?

No, the primary key does not have to be an integer; it’s just very common that it is. As an example, we have User ID’s here that can have leading zeroes and so must be stored in a varchar field. That field is used as a primary key in our Employee table.

Can a primary key be text?

You can not set primary key to text and ntext columns. But you can achiveve the same functionality by setting datatype as a varchar(8000). The difference is this column can now contain at most 8000 chars.

Can a varchar be a primary key?

It is perfectly acceptable to use a varchar column as the primary key. This is often the case when one uses a natural key that doesn’t happen to be an integer.

Can an ID be a string?

If it’s a generated Id by the DB and won’t be exchanged with other systems then it can be either. If it’s an Id which may be used by other systems and/or liveware then always store it as a string.

Can SQL Id be string?

15 Answers. Technically yes, but if a string makes sense to be the primary key then you should probably use it. This all depends on the size of the table you’re making it for and the length of the string that is going to be the primary key (longer strings == harder to compare).

Is GUID a good primary key?

GUIDs may seem to be a natural choice for your primary key – and if you really must, you could probably argue to use it for the PRIMARY KEY of the table. What I’d strongly recommend not to do is use the GUID column as the clustering key, which SQL Server does by default, unless you specifically tell it not to.

Is it good to use GUID as primary key?

GUIDs can be considered as global primary keys. Local primary keys are used to uniquely identify records within a table. On the other hand, GUIDs can be used to uniquely identify records across tables, databases, and servers.

Which is the primary key for a string?

primary string key = Correct DB relationships, 1 string key(The primary), and 1 string Index(The Primary). The other option is a typical int Key, but if the string HAS to be unique you’ll still probably need to add an index because of non-stop queries to validate or check that its unique.

Can a integer be used as a primary key?

Therefore we really cannot always choose an integer as a Primary Key, rather we go for a combination of 3, 4 or 5 attributes as the primary key for that tables. And those keys can be used as a foreign key when we would relate the records with some other table.

Which is better varchar or integer primary key?

Maybe even a country or state decides to change the spelling of its name – very unlikely, but not impossible. By using a surrogate key you avoid problems caused by having to change primary keys. VARCHAR vs. INT doesn’t tell much. What matter is the access pattern. On absolute terms, a wider key will always be worse than a narrow key.

Which is better an integer or an int?

When compared with INT though, few types can beat INT in narrowness, so INT usually wins that argument just by the fact that is only 4 bytes wide. But what really matters is the choice of clustered key. Often confused with the primary key, the two represent different notions and are not required to overlap.