209
votes

I have a mysqldump backup of my mysql database consisting of all of our tables which is about 440 megs. I want to restore the contents of just one of the tables from the mysqldump. Is this possible? Theoretically, I could just cut out the section that rebuilds the table I want but I don't even know how to effectively edit a text document that size.

20
FWIW, you could also use mydumper. This creates a logical dump like mysqldump, but it outputs separate files per table, and it can do both the dumping and the loading multi-threaded, so it takes less time.Bill Karwin

20 Answers

310
votes

You can try to use sed in order to extract only the table you want.

Let say the name of your table is mytable and the file mysql.dump is the file containing your huge dump:

$ sed -n -e '/CREATE TABLE.*`mytable`/,/Table structure for table/p' mysql.dump > mytable.dump

This will copy in the file mytable.dump what is located between CREATE TABLE mytable and the next CREATE TABLE corresponding to the next table.

You can then adjust the file mytable.dump which contains the structure of the table mytable, and the data (a list of INSERT).

135
votes

I used a modified version of uloBasEI's sed command. It includes the preceding DROP command, and reads until mysql is done dumping data to your table (UNLOCK). Worked for me (re)importing wp_users to a bunch of Wordpress sites.

sed -n -e '/DROP TABLE.*`mytable`/,/UNLOCK TABLES/p' mydump.sql > tabledump.sql
55
votes

This can be done more easily? This is how I did it:

Create a temporary database (e.g. restore):

mysqladmin -u root -p create restore

Restore the full dump in the temp database:

mysql -u root -p restore < fulldump.sql

Dump the table you want to recover:

mysqldump restore mytable > mytable.sql

Import the table in another database:

mysql -u root -p database < mytable.sql

12
votes

A simple solution would be to simply create a dump of just the table you wish to restore separately. You can use the mysqldump command to do so with the following syntax:

mysqldump -u [user] -p[password] [database] [table] > [output_file_name].sql

Then import it as normal, and it will only import the dumped table.

9
votes

One way or another, any process doing that will have to go through the entire text of the dump and parse it in some way. I'd just grep for

INSERT INTO `the_table_i_want`

and pipe the output into mysql. Take a look at the first table in the dump before, to make sure you're getting the INSERT's the right way.

Edit: OK, got the formatting right this time.

8
votes
  1. Backup

    $ mysqldump -A | gzip > mysqldump-A.gz
    
  2. Restore single table

    $ mysql -e "truncate TABLE_NAME" DB_NAME
    $ zgrep ^"INSERT INTO \`TABLE_NAME" mysqldump-A.gz | mysql DB_NAME
    
7
votes

You should try @bryn command but with the ` delimiter otherwise you will also extract the tables having a prefix or a suffix, this is what I usually do:

sed -n -e '/DROP TABLE.*`mytable`/,/UNLOCK TABLES/p' dump.sql > mytable.sql

Also for testing purpose, you may want to change the table name before importing:

sed -n -e 's/`mytable`/`mytable_restored`/g' mytable.sql > mytable_restored.sql

To import you can then use the mysql command:

mysql -u root -p'password' mydatabase < mytable_restore.sql
4
votes

One possible way to deal with this is to restore to a temporary database, and dump just that table from the temporary database. Then use the new script.

4
votes
sed -n -e '/-- Table structure for table `my_table_name`/,/UNLOCK TABLES/p' database_file.sql > table_file.sql

This is a better solution than some of the others above because not all SQL dumps contain a DROP TABLE statement. This one will work will all kinds of dumps.

3
votes

This tool may be is what you want: tbdba-restore-mysqldump.pl

https://github.com/orczhou/dba-tool/blob/master/tbdba-restore-mysqldump.pl

e.g. Restore a table from database dump file:

tbdba-restore-mysqldump.pl -t yourtable -s yourdb -f backup.sql

3
votes

Table should present with same structure in both dump and database.

`zgrep -a ^"INSERT INTO \`table_name" DbDump-backup.sql.tar.gz | mysql -u<user> -p<password> database_name`

or

`zgrep -a ^"INSERT INTO \`table_name" DbDump-backup.sql | mysql -u<user> -p<password> database_name`
2
votes

This may help too.

# mysqldump -u root -p database0 > /tmp/database0.sql
# mysql -u root -p -e 'create database database0_bkp'
# mysql -u root -p database0_bkp < /tmp/database0.sql
# mysql -u root -p database0 -e 'insert into database0.table_you_want select * from database0_bkp.table_you_want'
1
votes

Most modern text editors should be able to handle a text file that size, if your system is up to it.

Anyway, I had to do that once very quickly and i didnt have time to find any tools. I set up a new MySQL instance, imported the whole backup and then spit out just the table I wanted.

Then I imported that table into the main database.

It was tedious but rather easy. Good luck.

1
votes

You can use vi editor. Type:

vi -o mysql.dump mytable.dump

to open both whole dump mysql.dump and a new file mytable.dump. Find the appropriate insert into line by pressing / and then type a phrase, for example: "insert into `mytable`", then copy that line using yy. Switch to next file by ctrl+w then down arrow key, paste the copied line with pp. Finally save the new file by typing :wq and quite vi editor by :q.

Note that if you have dumped the data using multiple inserts you can copy (yank) all of them at once using Nyy in which N is the number of lines to be copied.

I have done it with a file of 920 MB size.

1
votes

I tried a few options, which were incredibly slow. This split a 360GB dump into its tables in a few minutes:

How do I split the output from mysqldump into smaller files?

1
votes

The 'sed' solutions mentioned earlier are nice but as mentioned not 100% secure

  • You may have INSERT commands with data containing: ... CREATE TABLE...(whatever)...mytable...

  • or even the exact string "CREATE TABLE `mytable`;" if you are storing DML commands for instance!

(and if the table is huge you don't want to check that manually)

I would verify the exact syntax of the dump version used, and have a more restrictive pattern search:

Avoid ".*" and use "^" to ensure we start at the begining of the line. And I'd prefer to grab the initial 'DROP'

All in all, this works better for me:

sed -n -e '/^DROP TABLE IF EXISTS \`mytable\`;/,/^UNLOCK TABLES;/p' mysql.dump > mytable.dump
0
votes

Get a decent text editor like Notepad++ or Vim (if you're already proficient with it). Search for the table name and you should be able to highlight just the CREATE, ALTER, and INSERT commands for that table. It may be easier to navigate with your keyboard rather than a mouse. And I would make sure you're on a machine with plenty or RAM so that it will not have a problem loading the entire file at once. Once you've highlighted and copied the rows you need, it would be a good idea to back up just the copied part into it's own backup file and then import it into MySQL.

0
votes

The chunks of SQL are blocked off with "Table structure for table my_table" and "Dumping data for table my_table."

You can use a Windows command line as follows to get the line numbers for the various sections. Adjust the searched string as needed.

find /n "for table `" sql.txt

The following will be returned:

---------- SQL.TXT

[4384]-- Table structure for table my_table

[4500]-- Dumping data for table my_table

[4514]-- Table structure for table some_other_table

... etc.

That gets you the line numbers you need... now, if I only knew how to use them... investigating.

0
votes

You can import single table using terminal line as given below. Here import single user table into specific database.

mysql -u root -p -D my_database_name < var/www/html/myproject/tbl_user.sql

-1
votes

I admire some of the ingenuity here, but there is literally no reason to use sed at all to address the OP's question.

The comment "use --one-database" is the correct answer, built into MySQL/MariaDB. No need for third-party hacks.

mysql -u root -p databasename --one-database < localhost.sql will just import the desired database.

I also found in some cases, when using this to import a series of databases, it would create the next database in the list for me (but not put anything in it). Not sure why it did that, but it made the restore easier.

With this command, enter the password interactively and it will import the requested database.