SQL Server Design Normalized Database Schema

Creating a generalized database schema in SQL Server involves organizing data into tables and defining relationships between them to reduce redundancy and ensure data integrity. 

Here is a step-by-step process for creating a generalized database schema,

Identify Entities

Identify the main entities- These are the key features or concepts in your application domain. For example, in an e-commerce application, companies can add Customers, Products, Orders, and so on.

Define relationships

Identify relationships between entities- Identify how the companies interact with each other. Relationships can be one to one, one to many, or many to many.
Use foreign keys- Define foreign keys in tables to establish relationships. For example, an Order may have a CustomerID that accesses the Customer table.

Normalize the Schema

First Normal Form (1NF)- Ensure that each table has a primary key and all columns have atomic (non-divisible) values. Avoid repeating groups or orders in different columns.

Second Normal Form (2NF)- Ensure that any non-key columns are completely dependent on the entire primary key. If necessary, split the tables further to accomplish this.

Third Normal Form (3NF)- Remove columns that do not depend on the primary key, and move them to separate tables if necessary.

Design Table Structure

Define Columns- For each table, identify the attributes (columns) that describe the object or relationship. Make sure that each column represents one block of data (atomicity).
Select appropriate datatype- Select the appropriate SQL Server data type (e.g., INT, VARCHAR, DATE, DECIMAL etc.) based on the data type and expected values.

Create Primary and Foreign Keys

Primary keys- Define primary keys for each table to uniquely identify each row. This can be a single color or a composite key (multiple colors).
Foreign keys- Use foreign keys to establish relationships between tables. A foreign key refers to the primary key of another table to ensure the integrity of the specification.

Example- 

Here is a simplified example of an e-commerce application,

Customer table-

CREATE TABLE Customer (
   CustomerID INT PRIMARY KEY,
   FirstName VARCHAR(50),
   LastName VARCHAR(50),
   Email VARCHAR(100) UNIQUE
   -- Other customer attributes
);

Product table-

CREATE TABLE Product (
   ProductID INT PRIMARY KEY,
   ProductName VARCHAR(100),
   Price DECIMAL(10, 2),
   -- Other product attributes
);

Order table-

CREATE TABLE Order (
   OrderID INT PRIMARY KEY,
   CustomerID INT FOREIGN KEY REFERENCES Customer(CustomerID),
   ProductID INT FOREIGN KEY REFERENCES Product(ProductID),
   OrderDate DATE,
   TotalAmount DECIMAL(10, 2),
   -- Other order attributes
);

Normalize Further (if necessary) 

Consider further normalization: If a table exhibits redundancy or nonatomic properties, consider further normalization to higher normal forms (e.g., 4NF or 5NF).

Normalizing a database structure in SQL Server involves creating accurate structures, defining objects and relationships, regularizing tables, and ensuring data consistency through special foreign interfaces This step which you will follow helps to achieve a robust and efficient database design that best supports your application's needs.

Also, Read: How to use SQL Server indexing to optimize query performance?