Re: Demo: Db For Dummies

From: Neo <neo55592_at_hotmail.com>
Date: 14 Nov 2004 18:52:34 -0800
Message-ID: <4b45d3ad.0411141852.222d62@posting.google.com>

While the XDb2 scripts appears simple enough for dummies, it creates the equivalent of the following RM schema (actually it further normalizes the name column of various tables, and then normalizes the symbols across all names). I have used "->" notation instead of ID values to make it easier to follow:

T_Person
name skin hair

----  --------------  ----
john  ->black         ->red,blue
mary  ->white,smooth  ->red,silky,smooth

T_Skin
ID

---

black
white,smooth

T_SkinColor (each skin can have any number of colors)

skin            color
----            ------


->black         ->black

->white,smooth ->white

T_SkinTexture (each skin can have any number of textures) skin texture
------------ --------
->white,smooth ->smooth

T_Hair
ID

---

red,blue
red,silky,smooth

T_HairColor (each hair can have any number of colors)

hair                color
------------------  -------


->red,blue          ->red

->red,blue          ->blue

->red,silky,smooth ->red

T_HairTexture (each hair can have any number of textures)

hair                 texture
------------------   -----

->red,silky,smooth ->silky
->red,silky,smooth ->smooth

T_Color
name

---

red
blue
black
white

T_Texture
name

---

smooth
silky

That XDb2's simple script creates a schema similar to above can be corroborated by looking at the same things in the tree view at www.xdb2.com/example/ex005.asp

When one compares RM's script/queries to XDb2's, it is easy to see why it is for Dummies, and RM is not. Received on Sun Nov 14 2004 - 20:52:34 CST