Cause
An attempt was made to drop a parent key column.
An attempt was made to drop a parent key column.
Drop all constraints referencing the parent key column, or specify CASCADE CONSTRAINTS in statement.
Try the following links for this error:
http://docs.oracle.com/cd/E16655_01/server.121/e26079/e12700.htm
https://community.oracle.com/message/1134721
https://community.oracle.com/message/1298362
https://community.oracle.com/message/4284437
https://community.oracle.com/message/11343879
https://community.oracle.com/message/338635
https://community.oracle.com/message/10974351
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