Documentation:Attribute or Data Type Conversion

Evolving from one data type to another is not automatically available in Mdriven due to the side effects of conversions.

Mdriven provides different options for converting data types,

1. Using FormerNames property setting.
2. Using a method.
3. Using derived attributes (Recommended).
4. Using SafeCast.

Important to know before performing a conversion

• Data conversions have to be done meticulously that as they can result in data loss. Backup your database before performing any conversions.

Using FormerNames property setting

This solutions involves renaming the attribute.

1. Set New Type on Attribute.

2. Rename the attribute to a new name and make sure to check Set Former Name checkbox

   When you rename an attribute, the previous attribute will be dropped or destroyed and attribute with new name is created.

   Checking the Set Former Name checkbox will add the previous attribute name in the Database property setting FormerNames.

3. Upload model.

MDriven evolver will try to transform and transfer the transformed data from the old attribute to the new attribute.

4. After checking and making sure the data has been successfully transformed, repeat step 2 and step 3 renaming the attribute to its previous name.

Using Method

Using a method can be more useful in scenarios where you want to be more explicit about your conversion or want to combine data of two attributes into one.

1. Start by adding a method to a class.

2. Go to method body and use EAL expressions for your transformation.

3. While the TurnKey and Server applications are running, open debugger.

4. Run method in Action mode for the instances you would like to perform transformations on.

5. Don't forget to save after executing the expression.

Using Derived Attributes (Recommended)

Using derived attributes ensures there are no side effects on your data. With this option current data is retained and you can try other data conversions and transformations without affecting the data.

You can use the new data attributes with the old data type attributes, incase you change your mind, just delete the new derived attribute and continue using your old data type attribute.

Deleting a derived attribute will not have any effect on your data in the database.

Use derived attributes to also test out other transformations or combination of attributes with out side effects.

Derived attributes ensures that current data is retained in its state of truthfulness and new type is also available

Derived attributes can also be used for complex transformations.