worksofliam / db2Model

Db2 for i model generator

db2Model

db2Model is a model generator for Db2 for i tables. It's a simple command line tool that generates JavaScript classes which can be used as a simple ORM.

db2Model can create:

• a class for the table specified
• static methods to fetch a row based on the primary or unique keys
• instance methods to fetch models based on foreign references keys
• instance methods to update and delete based on primary or unique keys
• classes for tables referenced in foreign keys.
• documentation for each class, instance method and static method.
• a class with methods to call stored procedures for a chosen schema

db2Model is using the odbc driver to connect, which must be installed onto the system running this script.

Usage

Creating Models

$ node index models SAMPLE DEPARTMENT

The following environment variabes are needed to connect: ISYS, IUSER, IPASS
Connecting to xxx with xxx.

Defined table DEPARTMENT
Defined table EMPLOYEE
Written to "models/Department.js".
Written to "models/Employee.js".

The reason Employee.js is created here is because the DEPARTMENT table has the column mgrno which references to the EMPLOYEE table. It also creates getEmployee inside of the Employee class as you can see below.

  const Department = require('./models/Department.js');

  const SupportDept = await Department.Get('E01');
  assert(SupportDept.deptname === "SUPPORT SERVICES");

  const ParentDept = await SupportDept.getDepartment();
  assert(ParentDept.deptno === "A00");

  //getEmployee returns an Employee class
  const SupportManager = await SupportDept.getEmployee();
  assert(SupportManager.firstnme === 'JOHN');

After you have generated your Models you can easily change the class properties without affecting the way the data is retrieved - which is great if you mostly have short-name columns.

Created procedure classes

db2Model can create classes with methods to call stored procedures in a chosen schema. This example generates functions for calling all stored procedures in QSYS - even though most of them are useless to regular developers.

$ node index procs QSYS
The following environment variabes are needed to connect: ISYS, IUSER, IPASS

Connecting to seiden.iinthecloud.com with alan3.

(node:6642) Warning: N-API is an experimental feature and could change at any time.
Fetching columns for QSYS/CREATE_SQL_SAMPLE.
Fetching columns for QSYS/CREATE_XML_SAMPLE.
...
Written to "models/QSYS.js".

And is now callable like so:

  const QSYS = require('./models/QSYS.js');

  try {
    await QSYS.create_sql_sample("SAMPLE");
  } catch (e) {
    console.log('Sample tables may already exist in SAMPLE schema.');
  }

Tests

There is a simple unit test provided. The test will try to create the Db2 for i sample tables in the SAMPLE schema.

>  node test.js

The following environment variabes are needed to connect: ISYS, IUSER, IPASS
Connecting to xxx with xxx.

Sample tables may already exist in SAMPLE schema.
Defined table DEPARTMENT
Defined table EMPLOYEE
Written to "models/Department.js".
Written to "models/Employee.js".
Tests pass