ORA-01452

Error: ORA-01452: cannot CREATE UNIQUE INDEX; duplicate keys found

Causa: A CREATE UNIQUE INDEX statement specified one or more columns that currently contain duplicate values. All values in the indexed columns must be unique by row to create a UNIQUE INDEX.

Acción: If the entries need not be unique, remove the keyword UNIQUE from the CREATE INDEX statement, then re-execute the statement. If the entries must be unique, as in a primary key, then remove duplicate values before creating the UNIQUE index.