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copied!<p>++ For the answers above.</p> <p>You should start thinking about the <em>keys</em> of these tables now. Each table should have <em>something</em> that will serve to uniquely identify a row -- done sensibly this will ensure that you can't get duplicate rows which would mess up your data.</p> <p>Here's a really simple example.</p> <pre><code>CREATE TABLE Parts ( [PartNumber] INT , [PartDescription] VARCHAR(50) ) </code></pre> <p>The PartNumber column would make a really good PRIMARY KEY (Assuming that no two parts thet you will ever have would have the same PartNumber) A property that uniquely defines a row and has meaning in and of itself is an example of a NATURAL KEY</p> <pre><code>CREATE TABLE Kits ( [KitNumber] INT , [KitDescription] VARCHAR(50) ) </code></pre> <p>Again -- KitNumber would be a good primary key. If there wasn't a NATURAL KEY for kits then you would probably make the KitNumber a simple Auto Incrementing SURROGATE KEY.</p> <p>Now to the more complicated table. The one that models the link between Parts and Kits. (Kits are made of parts).</p> <pre><code>CREATE TABLE KitParts ( [KitNumber] INT , [PartNumber] INT ) </code></pre> <p>So the only information this table contains is the links between Kits and Parts. What should the PRIMARY KEY be?</p> <p>If you think about the thing that uniquely identifies a row is the COMBINATION of the two columns. Therefore the NATURAL KEY is both ([KitNumber] and [PartNumber]). This is called a COMPOSITE KEY.</p> <p>Also this table should add some FOREIGN KEY Constraints. For example, [KitNumber] should never contain a value that doesn't exist in the Kits table.......</p> <p>Good luck. Welcome to SQL Development.</p>

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