The primary key is in important factor for any relational database. It plays a vital role. It has numerous functionalities. On a table we can create a primary key in different ways. But it is very important to choose an appropriate primary key. This article describes about the primary key and how to make a good primary key. Summary of the article:
- What is a Great Primary Key?
- How to make a Great Primary Key?
What is a Great Primary Key?
A primary key uniquely identifies each record within a table. But this is only a half story. The main purpose of a primary key is to make a link between others table for others information’s. In this sense, the primary key is a simple pointer between related records in different tables. As such, the primary-key value has no meaning to the user and no association to the data to which it’s assigned.
How to make a Great Primary Key?
When we make a primary then we should consider the following steps-
- The primary key value must be unique
- The primary key value can’t be null
- The primary key value must exist when the record is created
- The primary key must remain stable—you can’t change the primary-key field(s)
- The primary key should consist of one column whenever possible or compact
- The data type should be either an integer or a short, fixed-width character
- If you’re using a character data type, the primary key should exclude differential capitalization, spaces, and special characters, which might be difficult to remember
- Don’t be confused on primary key and unique key. Both have some difference
A good primary key can improve the table performance and can reduce the query execution time. That’s why we need to consider that during database design. Take time and try to select best primary key which is suitable for the system.