Relationships

..\sdk\sql.jdbc\tutorials\JDBC_Tutorial2.java

Now we will build some table/file relationships using the c-treeACE SQL JDBC Interface.

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 indices 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:

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

Note our simple mainline:

import java.sql.*;

import java.io.*;

public class JDBC_Tutorial2 {

   static Connection conn;

   static Statement stmt;

   //

   // main()

   //

   // The main() function implements the concept of "init, define, manage

   // and you're done..."

   //

   public static void main (String[] args)

      throws java.io.IOException

   {

      Initialize();

      Define();

      Manage();

      Done();

      System.out.print("\nPress <ENTER> key to exit . . .");

      System.in.read();

      System.exit(0);

   }

We suggest opening the source code with your own editor.

Continue now to review these four steps.