Synchronization after Modification of the Data Diagram
Newly created entities, associations, and attributes in the data diagram
The corresponding elements are created in the relational diagram, according to the rules used in the first synchronization.
Entities, associations, or attributes deleted from the data diagram
The corresponding elements are deleted in the database. For example, when an attribute is deleted in the data diagram, the corresponding column(s) are also deleted.
Modified attribute characteristics
Modifications made to the characteristics of an attribute (type, length, decimal places, etc.) are reflected in the corresponding column in the relational diagram.
If the value of a characteristic of a column has been changed directly in the relational diagram, it will be preserved.
Modified name of an attribute, entity, or association
Modifications made to the name of an attribute, entity, or association are not reflected in the corresponding object in the relational diagram.
Modified maximum multiplicity of an association
If the maximum multiplicity of an association was 1, resulting in the creation of a migratory column, and has been changed to N, the migratory column is deleted and the table mapped by the maximum multiplicity of N is created.
Modified association links
Association R no longer concerns entity B, but does concern entity C.
In this case, the migratory column for B in A is no longer mapped.
• It is deleted.
• A migratory column from C is created.