How to Add an Identity to An Existing Column in SQLite

Understanding Identity Columns

Identity columns in SQLite automatically assign unique, auto-incrementing values to each row in a table, often serving as primary keys. Unlike SQL Server, SQLite doesn’t offer native identity column support. Developers typically implement this functionality using techniques like AUTOINCREMENT or row counting to ensure data integrity and efficient data management....

How to Add an Identity to An Existing Column in SQLite

To add an identity to an existing column in SQLite, developers can use ALTER TABLE with AUTOINCREMENT, create a temporary table, copy data, add an identity column, or update identity values based on row positions. We will explore the three approaches:...

Setting up an Environment

Different approaches to add identity to an existing column are:...

1. Using ALTER TABLE with AUTOINCREMENT

In this approach, we’ll utilize the ALTER TABLE statement along with the AUTOINCREMENT keyword to add an identity column to an existing table....

2. Create a Temporary Table with Identity Column and Copy Data

This approach involves creating a temporary table with an identity column, copying data from the original table, and then renaming the temporary table to replace the original one....

3. Using a Temporary Table and ALTER TABLE to Add Identity

In this approach, we’ll create a temporary table, copy data from the original table, add an identity column using ALTER TABLE, and then copy the data back....

Conclusion

While adding an identity column to an existing table in SQLite is easy and takes just a few simple steps, it is imperative to pay close attention to data integrity. The procedure detailed in this article along with some care will help you to add an identity column to your SQLite database and improve the structure of your tables. Keep in mind to always take a backup of your database before making any structural changes and test your changes thoroughly to make sure they are in compliance with your requirements. Through a proper knowledge of SQLite functionalities and the appropriate SQL commands, you can skillfully maintain and optimize your database schema and data management workflows....