How can I change the type of a Core Data entity column programmatically? For example, form String to Int 16. The entity can be assumed empty (no data row).
How can I change the type of a Core Data entity column programmatically? For
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How can I change the type of a Core Data entity column programmatically? For example, form String to Int 16. The entity can be assumed empty (no data row).
Firstly, it’s not an SQL column, it’s the attribute of an entity. Attributes have behaviors, columns in SQL do not.
In answer to your question, once a data model model has been used to write data to a persistent store file (sqlite store or other formats) it cannot altered programatically. If you change an attribute, you need to perform a version migration.
See: Core Data Model Versioning and Data Migration Programming Guide for details.
A little general advice: Core Data is not SQL. Entities are not tables. Objects are not rows. Attributes are not columns. Relationships are not joins. Core Data is an object graph management system that may or may not persist the object graph and may or may not use SQL far behind the scenes to do so. Trying to think of Core Data in SQL terms will cause you to completely misunderstand Core Data and result in much grief and wasted time.