How to convert a database table from a denormalized state to 1NF?

To convert a database table from a denormalized state to First Normal Form (1NF), you need to ensure that the table meets the following criteria:

1. Eliminate Duplicate Columns: Each column should contain only atomic (indivisible) values.
2. Create Separate Tables for Each Group of Related Data: Identify primary keys and separate tables based on these keys.
3. Identify Primary Keys: Ensure each row can be uniquely identified.

Steps to Convert to 1NF:

1. Analyze the Existing Table: Look for repeating groups or arrays within a single column.
2. Split Columns: Break down columns that contain multiple values into separate columns or rows.
3. Define Primary Keys: Assign a unique identifier to each row if not already present.

Example:

Consider a denormalized table named Orders:

OrderID	CustomerName	OrderDate	Items
1	John Doe	2023-01-01	Pen, Notebook, Pencil
2	Jane Smith	2023-01-02	Book

To convert this to 1NF:

1. Split the Items Column: Create a new table for items.
2. Define Primary Keys: Use OrderID and ItemID as composite keys.

Normalized Tables:

Orders Table:

OrderID	CustomerName	OrderDate
1	John Doe	2023-01-01
2	Jane Smith	2023-01-02

OrderItems Table:

OrderID	ItemID	ItemName
1	1	Pen
1	2	Notebook
1	3	Pencil
2	1	Book

Recommendation for Cloud Services:

For managing and normalizing databases in the cloud, consider using Tencent Cloud's Database Management Service (DMS). It provides tools for database migration, schema design, and optimization, which can facilitate the process of converting a denormalized table to 1NF.