Database Independent Record Level Access via SQL (In Development)

Profound.js Connector provides much of the same Record Level Access support when working with any of the supported databases. Below is a list of the functions that are not supported with this connector:

Override database file support is not supported
Using files with level checking is not supported
QTEMP library/schema is not supported
Record Locking is not supported
Fetching records by relative record number is not supported
Some of the INFDS (Information Data Structure) fields are not supported

For more information about RLA capabilities, see Record Level Access API.

All you need to do to begin using RLA/SQL functions within your pjs programs is to create the DbDefn module. This module enables you to use RLA functions in lieu of writing a whole lot of sql, and it also allows for database independence.

To create a module we need to name and describe some key parts of that table (or view/logical).

Module File name --> example product.DbDefn.js
1. The module file name must end with .DbDefn.js
2. The first part of the name "product" is how your pjs program(s) will reference it.
Describing the table:
1. useSQL - required - Set this to true if you want this to enable RLA/SQL functionality, else it will use the IBM i RLA functionality
2. dbObject - required - Set this to the actual database object name, can be the name of a table or a view..
3. uniqueKey - required - This is needed to be able to read 1 record at a time in a uniquely specific sequence.
  1. field - the name of the column
  2. ascending: true or false if the column should be sorted in ascending order
4. dbSchema - optional - Set this to the actual database schema
5. format - optional - When converting RPG programs to Profoundjs programs this is required. This is the record format name of the IBM i table.
6. overrides - optional - this is where you can override specific fields types and values
  1. There are several reasons for using this. Here are a few:
    1. The database does not support storage of that type of field (such as a Time type field)
    2. The database stores 2 separate fields for Date and Time, but you want to put them together as a single DateTime field
    3. You have choose to store date or time values as string, but you want the UI to show them as true dates and times.

** Important note: table names and field names are case sensitive **

Below is an example of that PRODUCT table. It was placed directly under the modules folder. If you have a lot of tables, you will want to better organize them.

This example also shows a couple different examples on how you can use the override.

Field named "prcatid" that is stored in the database as character, but will be referenced within the pjs program as decimal.
Field name "prtime" that is stored in the database as character, but will be referenced with the pjs program as time.

module.exports = {
  useSQL: true,
  dbObject: "product",
  format: "product",
  uniqueKey: [
    { field: "prid", ascending: true }
  ],
  overrides: {
    prcatid: {
      type: "decimal",
      length:5,
      decimals:0,
      transformToDb: function() { return this.toString().padStart(5,"0") },
      transformFromDb: function() { return Number(this) },
    },
    prtime: {
      type: "time",
      transformToDb: profound.utils.timeToCharTransform,
      transformFromDb: profound.utils.charToTimeTransform
    }
  }
}

If you have had a pjs program you don't have to do anything to it, as long as it does not use any of the unsupported functions.

Here is a simple pjs program that reads all the records of a table. It is just like any other pjs program using RLA.

function products() {
    pjs.defineTable("product", { read: true, keyed: true });
    product.positionTo(0);

    var data = [];
    var record = product.fetch();
    while (!pjs.endOfData()) {
        data.push(record);
        record = product.fetch();
    }
   
    console.log(JSON.stringify(data,null,2));
}

exports.run = products;