VCL/CLX Developers Guide

Relationships

sdk\ctree.vcl.cbuilder\tutorials\Tutorial2.cpp

Now we will build some table/file relationships using the FairCom DB CodeGear VCL ISAM Component Framework - CBuilder.

This tutorial will advance the concepts introduced in the first tutorial by expanding the number of tables. We will define key columns/fields and create specific indexes for each table to form a relational model database.

Like all other examples in the c-tree tutorial series, this tutorial simplifies the creation and use of a database into four simple steps: Initialize(), Define(), Manage(), and You’re Done() !

Tutorial #2: Relational Model and Indexing

Here we add a bit more complexity, introducing multiple tables, with related indices in order to form a simple "relational" database simulating an Order Entry system. Here is an overview of what will be created:

JDBC Relational Picture

Initialize() - Connects to the FairCom Database Engine.
Define() - Defines and creates the "custmast", "custordr", "ordritem" and the "itemmast" tables/files with related indexes.
Manage() - Adds some related rows/records to all tables/files. Then queries the database.
Done() - Disconnects from FairCom Database Engine.

Note our simple logic:

void __fastcall TForm1::FormShow(TObject *Sender)

{

Initialize();

Define();

Manage();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::FormCloseQuery(TObject *Sender, bool &CanClose)

{

CanClose = true;

Done();