“Not Null” constraints cannot be set or enforced through Iron Speed Designer. However, you can make fields mandatory on forms, meaning an application user must provide a value in order for the record to be inserted into the database. (See “Setting Code Generation Tag Properties” for details.) You can also provide default field values by entering a Default Value (see Data Conversion Options). To make sure the field is required at the database level, you will need to make changes to the schema at the database level.
Setting Field Display and Data Validation Options