Many-to-Many Relationship Table

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jordanw44 asked Sep 7, '12

Many-to-Many Relationship Table

I made a post yesterday here. After many hours, a severe headache, and some tylenol I have decided to try and see if I can get some help on this many-to-many relationship that I was suggested to try and use. I decided to define my tables a little better to hopefully provide you guys with some more and clearer information. Here is a screenshot:
![alt text][1]
How can I accomplish this with either a one-to-many or a many-to-many relationship table? Thanks!
[1]: /storage/temp/392-\capture.png

query table

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Answer 1 · 2012-09-07T16:49:14Z

SirSQL answered Sep 7, '12

Something like this what you are after? CREATE TABLE Computer ( Asset INT NOT NULL PRIMARY KEY , DefaultPrinterID INT , WristbandPrinter INT ) CREATE TABLE Printer ( PrinterID INT IDENTITY(1, 1) NOT NULL PRIMARY KEY , PrinterPath VARCHAR(15) ) CREATE VIEW ComputerPrinterReference AS SELECT c.Asset AS Asset , p.PrinterPath AS DefaultPrinter , p2.PrinterPath AS WristbandPrinter FROM Computer c INNER JOIN Printer p ON c.DefaultPrinterID = p.PrinterID INNER JOIN Printer p2 ON c.WristbandPrinter = p2.PrinterID GO

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jordanw44 commented · Sep 07, 2012 at 04:56 PM

@SirSQL on line 3, 4, and 5 you have "c.Aset AS Asset" etc... What exactly are you doing with this? It looks like you are declaring variables almost but I'm not sure if I am even on the right path.

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jordanw44 commented · Sep 07, 2012 at 05:50 PM

I see definite benefits in re-organizing my database like this. I would have to change a couple things around in one of my programs insert statments but this could be tremendously better in the end. I can see myself needing to know what computers are mapped to each printer as well so I will study up on my pivot's.

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Answer 2 · 2012-09-07T17:25:02Z

Grant Fritchey answered Sep 7, '12

No, something like this: ![alt text][1] Then you only put computer information into the computer table. You only put printer information into the printer table. The relationship table defines if it's a default wristband, hoozymawatchit or anything else. Then, the ComputerPrinter table brings them all together. This way you can get listings any way you want them. I will tell you, the one wrinkle is, if you want to output printers across the page for each computer, you'll need to use a type of query called a pivot. I leave that to you for additional homework. [1]: /storage/temp/393-manytomany.png

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