MySQLDump – How to Backup Subset of Rows in Specific Table

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I have a database (myDB) that holds some tables. During my backup process I have one of those tables that should be filtered. So I want to backup only a subset of rows inside table1, when I backup the entire database.

I am using mysqldump like this:

mysqldump -uUSER -pPASSWORD --routines --add-drop-database   --databases myDB --tables table1 -w "id<3"> myDB_BK.sql

The subset rows is correct for table1 but I dont have the entire database. Only the specified table1.

I've tried all combination with no success.

Any Idea in how to accomplish this task?

Best Answer

Dumping subsets of table data can only be done backing up individual tables.

I once answered a post entitled Is it possible to mysqldump a subset of a database required to reproduce a query?. In that post, I used mysqldump strictly against the tables in question.

The only thing you can do is to produce two dumps

mysqldump of the database without table1 (means you have to name all other tables (See my old post How do you mysqldump specific table(s)?)
mysqldump only table1 using -w or --where
concatenate the second dump to the first dump

Give it a Try !!!

Related Solutions

Mysql – Users complain that system runs slow when thesqldump is in progress

There is a known issue in Windows, that when you push a large file to another server all the memory ends up getting allocated to the System cache instead of the user processes. You can look in the Physical Memory (MB) section of task manager to see how much memory is allocated to the system cache.

This can be solved by backing up to a local disk, then having the remote machine pull that file.

MySQL – How to mysqldump Specific Tables

If you are dumping tables t1, t2, and t3 from mydb

mysqldump -u... -p... mydb t1 t2 t3 > mydb_tables.sql

If you have a ton of tables in mydb and you want to dump everything except t1, t2, and t3, do this:

DBTODUMP=mydb
SQL="SET group_concat_max_len = 10240;"
SQL="${SQL} SELECT GROUP_CONCAT(table_name separator ' ')"
SQL="${SQL} FROM information_schema.tables WHERE table_schema='${DBTODUMP}'"
SQL="${SQL} AND table_name NOT IN ('t1','t2','t3')"
TBLIST=`mysql -u... -p... -AN -e"${SQL}"`
mysqldump -u... -p... ${DBTODUMP} ${TBLIST} > mydb_tables.sql

Give it a Try !!!

UPDATE 2014-03-06 10:15 EST

@RoryDonohue pointed out to me that the GROUP_CONCAT function needs to have its max length extended. I added the session variable group_concat_max_len to my answer with a length max of 10K. Thanks, @RoryDonohue.

Best Answer

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Mysql – Users complain that system runs slow when thesqldump is in progress

MySQL – How to mysqldump Specific Tables

UPDATE 2014-03-06 10:15 EST

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