Creating tables in SQL Server is a fundamental task in database design.
SQL Server provides Transact-SQL (T-SQL) as a programming language to create and manage database objects.
In T-SQL, you can create a table using the SQL
CREATE TABLE statement followed by the table name and column definitions.
Creating a table with primary and foreign keys is a common task in SQL Server database design.
Here is the basic syntax to create a table:
CREATE TABLE table_name
For example, to create a table named Customers with columns for CustomerID, FirstName, LastName, Email, and PhoneNumber, you can use the following code:
CREATE TABLE Customers
To add constraints to the table, such as primary keys and foreign keys, you can modify the column definitions with additional keywords.
PRIMARY KEY is a unique identifier for each row in a table, which ensures that each row can be uniquely identified. In SQL, you can add a SQL primary key to a table using the
PRIMARY KEY constraint.
Here's an example of how to create a table named Orders with a primary key constraint on the OrderID column:
CREATE TABLE Orders
OrderID INT PRIMARY KEY,
In this example, the OrderID column is set as the primary key for the Orders table.
FOREIGN KEY is a constraint that establishes a link between two tables based on the values of a column in each table. In SQL, you can add a foreign key to a table using the
FOREIGN KEY constraint.
Here's an example of how to create a table named OrderDetails with a foreign key constraint on the OrderID column, which references the Orders table:
CREATE TABLE OrderDetails
OrderDetailID INT PRIMARY KEY,
FOREIGN KEY (OrderID) REFERENCES Orders(OrderID)
In this example, the OrderID column in the OrderDetails table is defined as a foreign key that references the OrderID column in the Orders table. This ensures that each row in the OrderDetails table corresponds to a valid order in the Orders table.