[http://www.equi4.com/images/metakit.gif]

MetaKit is a [C++] database library, and is used as the [persistence] engine underneath [WiKit].  If it works as intended, you'll never have to deal with any of it, because one of its goals is to help you stay out of trouble.

The homepage of MetaKit is:  http://www.equi4.com/metakit.html

[alove] -- Documentation for using MetaKit with the TCL extension Mk4tcl is at: http://www.equi4.com/metakit/tcl.html
 
[RLH] - A tutorial by Mark Roseman is at: http://www.markroseman.com/tcl/

[DDG]: Tiny [SQL] for Metakit provides [tsql4mk].

It was developed, and is actively supported, by [jcw].

See [MetaKit Tips and Tricks] for useful code snippets.
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[CMcC] Err, what happened to the old page?  Ah, found what I was after here: [mk4too]

''09nov05 [jcw] - There were two pages called "Metakit" in this wiki, due to some old renaming glitches.  I've manually adjusted things to resolve this (the "lost" copy was on page 478).  Below is the original text.''
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Metakit has its own (now closed, read-only) Wiki [http://www.equi4.com/metakit/wiki.cgi/] and home page [http://www.equi4.com/metakit.html].
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Metakit is the [persistence] engine for [Wikit], of course.

   * [Mark Roseman] has written a tutorial [http://www.markroseman.com/tcl/mktcl.pdf] on Metakit for Tcl developers.
   * [Mark Roseman]'s tutorial [http://www.markroseman.com/tcl/mktcl.html] in HTML.
   * detailed metakit documentation [http://www.equi4.com/metakit/tcl.html].
   * [OOMK] is the preferred oo metakit interface, written in [Snit], giving many more facilities than vanilla mk4tcl.
   * desultory (unofficial) documentation on an unsupported OO-like view interface called [mk4too]
   * [Riccardo Cohen]'s tutorial at http://support.articque.com/metakit/metakit_tutorial.html 

The [Metakit File Format].

The Tcl binding to Metakit is named [Mk4tcl].

It was claimed here that Mk4tcl is part of the [ActiveTcl] Batteries included release. This does not appear to be the case as of 8.4.2, 9 May 2003 - [Roy Terry]. Metakit ''is'' included in lib/mk4tcl as of tcl '''8.4.4''', but without documentation, it seems (Hof).

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'''[DGP]'''
For what it's worth, here are the points I found most
useful in the Roseman intro:

   * Use properties that define as small a unit of information as possible. 
   * Creating more views is a good thing.  Do that, don't muck up a single view with special cases. 
   * Moving data to/from a Tcl array is easy and familiar to Tclers. 
   * Emphasis that restructuring of a view layout means you can continue revising your data model as you go.  Just start coding; you can change it later.
   * Some discussion when subviews are good vs. additional views.

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"... many of the integrity
checks required in traditional database use are not required in Metakit,
because Metakit offers nested views -- a cleaner way to represent the
relationships often enforced by integrity constraints."



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"cleaner" is a matter of opinion, ask a relational database theorist.  I don't want to start those arguments here, just point out that if you use Metakit for a complex system, you '''should''' design first, and be very careful. - EMJ

[DKF]: "You '''should''' design first"?  That's actually true of any non-trivial program, you know... ;^)  ''An ounce of thought saves a ton of effort.''

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'''MetaKit Viewer'''
 
See also [dgmkviewer], a metakit viewer/editor in Tcl
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[Ruffy]

Can someone help me resolve what little thing I'm doing wrong;
Why does my SELECT statement render a zero resultset - when I know that many such ROWS exist?!

package require Mk4tcl
mk::file open tg info.db -readonly
set testName Stanley
set view [mk::view layout tg.books "name author isbn publisher"]
set rownums [mk::select tg.books name $testName]
puts "Size is : [llength $rownums]"


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[Category Database]
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[Category Package]
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