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Defining primary and foreign keys

A very important concept of relational databases is the use of primary and foreign keys. In this exercise, you will define a two new tables. A table Person, with a PRIMARY KEY and another table, History, with a PRIMARY KEY and a FOREIGN KEY referencing the Person table.

This exercise is part of the course

Hierarchical and Recursive Queries in SQL Server

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Exercise instructions

  • Define the primary key PersonID for Person of type INT.
  • Define the primary key OrderID for History.
  • Define the foreign key PersonID referencing the primary key of Person.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

CREATE TABLE Person (
  	-- Define the primary key for Person of type INT
  	___ ___ NOT NULL ___ ___,
	Firstname VARCHAR(255) NOT NULL,
	Lastname VARCHAR(255) NOT NULL,
);

CREATE TABLE History (   
    -- Define the primary key for History
  	OrderID INT ___ ___ ___ ___,
    Item VARCHAR(255) NOT NULL,
    Price INT NOT NULL,
  	-- Define the foreign key for History
    PersonID INT ___ ___ REFERENCES Person(___)    
);

SELECT * 
FROM History;
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