Data Dictionary

 

A Data Dictionary is a work environment for m-Power users. It contains the registered meta-data that describe the tables/fields/joins/rules needed to create applications. For each Data Dictionary, there is a corresponding server file directory containing all of the generated components for all of the applications created within that Data Dictionary. Within the Data Dictionary, individual applications are defined by application specifications. m-Power users may combine various applications to create robust Web applications for end users.

Data Dictionary Benefits

There are many benefits of the m-Power Data Dictionary concept:

  1. Define each table and field only once so that all applications generated with those fields will create correct/consistent field labels.
  2. Setup the table field joining/linking just once, ensuring correct/consistent joins for generated apps.
  3. Define External Objects once to ensure correct/consistent calls to external business logic.
  4. The one-time Data Dictionary setup makes m-Power much more useful as a business-user tool and not only a developer tool. An m-Power administrator can handle the setup and offer power/business users the opportunity to create their own applications with m-Power.
  5. m-Power's internal reporting can show application usage of tables, fields, and external objects.

Data Dictionary Setup

Before creating applications with m-Power, you'll need to perform some one-time setup in the Data Dictionary. You need to register the tables that you will use when you create applications. You might need to set the field descriptions and rules; some DB meta-data can be registered more easily than others. If you will join tables together with join fields, those fields need to be defined as m-Power Synonyms.

Please follow these steps to register your own database table to the Data Dictionary:

  1. Click on the "Manage Data" button in the Navigation Bar to access the "Manage Data" screen.
  2. Click the "Register Tables" button.
  3. If you know the schema (library) and table name, please enter it and click Accept.
  4. Otherwise, you can click the "Browse" button to browse schemas and then tables. When you click a listed table, it becomes registered to the Data Dictionary.

It can also be useful to properly set the field-level properties in the Data Dictionary. For example, you can set a field's description once, thereby setting it appropriately for each application that you build over that field. To set the field description, please follow these steps:

  1. Click on the "Manage Data" button in the Navigation Bar to access the "Manage Data" screen.
  2. Click the "Manage Tables" button.
  3. Click the "Fields" icon for the applicable table you would like to modify.
  4. Click the "Edit" icon for a field.
  5. Enter the appropriate field description for that field and click Accept to save that change.
  6. Repeat those steps for other fields as needed.
  7. Other attributes are definable at the field level in the Data Dictionary and are described in detail in the standard m-Power training class.

If you are planning to create an application that joins multiple tables together, you will need to create m-Power Synonyms to tell m-Power to allow joins on that field pair. Please note that this step is not necessary for those databases where fields that are intended to be joined from different tables have the exact same name. Fields with the same name in different tables are understood by m-Power to be joinable already. To create Synonyms, please follow these steps:

  1. Click on the "Manage Data" button in the Navigation Bar to access the "Manage Data" screen.
  2. Click the "Manage Tables" button.
  3. Click the "Fields" icon for the applicable table you would like to modify.
  4. Click the "Synonyms" icon for the field that requires the synonym.
  5. If there are any existing synonyms they will appear on this screen. Click the "Add Synonym" icon to add a synonym.
  6. Use the search boxes to find the field that will join to your original field. Click the plus icon.
  7. You will be returned to a listing of existing synonyms for your original field. If you need to create more synonyms, please repeat the process.

Note: Synonyms are reciprocal. If you create a synonym for FIELD1 to FIELD2, you do not need to create a synonym for FIELD2 to FIELD1, as one has already been created for you.

Data Dictionary Considerations

Some organizations use just one Data Dictionary for all of the applications they create. Others prefer to separate their applications logically or functionally. mrc recommends creating a Data Dictionary for each user community. For example, if you were creating applications for customers, that could be Data Dictionary CUSTOMERS. For employees, you could make another Data Dictionary named EMPLOYEES.

Other Data Dictionary concerns which might help determine how many Data Dictionaries are needed:

  • Application Security/Authentication. Each Data Dictionary can be secured in one of the following ways:
    • No user authentication.
    • Authenticate user against one DB table.
    • Authenticate as a DB user.
  • Sensitive Data. If the Human Resources staff should have access to just a certain set of tables that contain sensitive data only for HR staff usage, then it might be useful to create a separate Data Dictionary just for HR. m-Power users can be restricted to specific Data Dictionaries.

Learn more about the m-Power Build Process by clicking here.

Created: January 20, 2010 | Modified: December 3, 2013