How to import oracle dmp file and overwrite the original data

1. Repeat the import database already exists, the following two methods IMP and introducing IMPDP;

   
2. 2

   When IMP import  : If the table already exists, it will tell you can not create this table, because the table already exists. Meanwhile parameter full = y ignore = y that is all imported, all the data inserted into the table in dmp inside. In other words there is repeated, if the table has a primary key, because of the constraint violation is repeated, introducing unsuccessful, but can not be repeated in, this case is added into the cover.

   
3. 3

   Data Backup, use the command:

   exp user/user file=d:\user.dmp full=y

   When recovery, use the command:

   imp user/user FILE=d:\user.dmp fromuser=user touser=user full=y ignore=y

   
4. 4

   When introduced IMPDP  : parameter table_exists_action = replace deleted after coverage;

   table_exists_action options: {skip if the table already exists, skip and the next object; append data to increase table; truncate table is cut off, and give it to add new data; replace the existing table is deleted, and re-build the table additional data}

   
5. 5

   Data Backup, use the command:

   expdp user/user directory=dump_dir dumpfile=schema.dmp logfile=schema.log schemas=user job_name=exp_user_schema恢复时，使用命令：impdp user/user directory=dump_dir dumpfile=schema.dmp logfile=schema.log  table_exists_action=replace schemas=user content=all job_name=imp_schema 

   

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