I exported 2 identical databases(identical in terms of names and structures of tables) into two .sql files using mysqldump. I want to merge them into one file. However, both the databases have a 'Drop table' line before every table. What that means is if I import db1 and then db2, db1 tables are dropped before db2 tables are imported.
The files are huge and I am not able to open them in the editor. Also, there are 50 tables in each databases.
How can I ignore the Drop table command during mysql import?
All you need is to add --skip-add-drop-table option when using mysqldump.
$ mysqldump --databases --skip-add-drop-table -u root db1 > /tmp/qqq.2
So, there would not DROP TABLE IF EXISTS in sql files.
see docs of mysql on --skip-add-drop-table
If you do not want to make dump once again and you are using Linux you can go with:
awk '!/^DROP TABLE IF EXISTS/{print}' <dump.file> | mysql <db_name>
If you want to dump data once again you should pass --skip-add-drop-table to mysqldump utility.
I guess I don't see why a DROP TABLE statement should be problematic or why you need to merge dumps for two IDENTICAL databases.
That being said, you should probably just not add DROP TABLE in the initial dump. This would be controlled via flag use in your mysqldump command as noted in the documention at http://dev.mysql.com/doc/refman/5.5/en/mysqldump.html
This probably means you need to use --skip-opt flag if you were using default options (default is to run as if --opt flag is passed). You will then need to specify all flags within --opt that you still want to use.
Related
I have a database with three tables .
I want to create a backup file of some records in the second table :
mysqldump --opt --user=${USER} --password=${PASS} --databases ${DATABASE} --where="id = $1" mydb Table2 > FILE.sql
the problem is in the restore by using this code .
mysql --user=${USER} --password=${PASS} ${DATABASE} < FILE.sql
It deletes the entire database and inserts I only selected records from the previous code .
I wish only the selected records restore without deleting the rest .
You are using the [--databases][1] flag which is used when dumping several databases and should not be used when you want to dump only a single table.
Dump several databases. Normally, mysqldump treats the first name
argument on the command line as a database name and following names as
table names. With this option, it treats all name arguments as
database names. CREATE DATABASE and USE statements are included in the
output before each new database.
Avoid using that argument and for good measure use --no-create-info or simply -t instead to make sure create table / drop table commands are not in the dump file
You should try using the --skip-add-drop-table option when using mysqldump.
http://dev.mysql.com/doc/refman/5.5/en/mysqldump.html
This would prevent a drop table entry being added to the sql export.
I need to restore a dumped database, but without discarding existing rows in tables.
To dump I use:
mysqldump -u root --password --databases mydatabase > C:\mydatabase.sql
To restore I do not use the mysql command, since it will discard all existing rows, but instead mysqlimport should do the trick, obviously. But how? Running:
mysqlimport -u root -p mydatabase c:\mydatabase.sql
says "table mydatabase.mydatabase does not exist". Why does it look for tables? How to restore dump with entire database without discarding existing rows in existing tables? I could dump single tables if mysqlimport wants it.
What to do?
If you are concerned with stomping over existing rows, you need to mysqldump it as follows:
MYSQLDUMP_OPTIONS="--no-create-info --skip-extended-insert"
mysqldump -uroot --ppassword ${MYSQLDUMP_OPTIONS} --databases mydatabase > C:\mydatabase.sql
This will do the following:
remove CREATE TABLE statements and use only INSERTs.
It will INSERT exactly one row at a time. This helps mitigate rows with duplicate keys
With the mysqldump performed in this manner, now you can import like this
mysql -uroot -p --force -Dtargetdb < c:\mydatabase.sql
Give it a Try !!!
WARNING : Dumping with --skip-extended-insert will make the mysqldump really big, but at least you can control each duplicate done one by one. This will also increase the length of time the reload of the mysqldump is done.
I would edit the mydatabase.sql file in a text editor, dropping the lines that reference dropping tables or deleting rows, then manually import the file normally using the mysql command as normal.
mysql -u username -p databasename < mydatabase.sql
The mysqlimport command is designed for dumps created with the mysql command SELECT INTO OUTFILE rather than direct database dumps.
This sounds like it is much more complicated than you are describing.
If you do a backup the way you describe, it has all the records in your database. Then you say that you do not want to delete existing rows from your database and load from the backup? Why? The reason why the backup file (the output from mysqldump) has the drop and create table commands is to ensure that you don't wind up with two copies of your data.
The right answer is to load the mysqldump output file using the mysql client. If you don't want to do that, you'll have to explain why to get a better answer.
I'm using the following command to create an incremental backup in MySQL
mysqldump -uusername -ppassword db_name --flush-logs > D:\dbname_incremental_backup.sql
However the sql file is as big as a complete backup, and obviously importing it takes a long time as well. Could anybody tell me how to create incremental backups and import just the new data from each incremental backup rather than the whole database again?
I have read all the related articles in dev.mysql.com but still can not understand how to do it.
mysqldump only creates full backups. There's no built-in functionality for incremental backups.
For that sort of thing you probably want Percona xtrabackup but that will only work with InnoDB tables. This is usually not an issue since using MyISAM tables is considered extremely harmful.
By default a mysql dump will drop tables making an incremental update impossible. If you open up the resulting file, you will see something like:
DROP TABLE IF EXISTS `some_table_name`;
You can create a dump without dumping and creating new tables using the --no-create-info option. To make your dump friendly to incremental imports, you should also use --skip-extended-import which will break inserts out into one insert statement per row. Combined with using --force on the import will mean that inserts for rows that exist will fail but the import will continue. You will end up seeing errors in the logs for rows that already exist, but new rows will be inserted as desired.
You should be able to export with the following command (I also recommend not typing the password in the command so that it won't appear in your history)
mysqldump -u username -p --no-create-info --skip-extended-insert db_name --flush-logs > D:\dbname_incremental_backup.sql
You can then import with the following command:
mysql -u username -p --force db_name < D:\dbname_incremental_backup.sql
I'm regularly running mysqldump against a Drupal database and man, those cache tables can get huge. Considering that the first thing I do after reloading the data is clear the cache, I'd love it if I could just skip dumping all those rows altogether. I don't want to skip the table creation (with --ignore-tables), I just want to skip all those rows of cached data.
Is it possible to tell mysqldump to dump the CREATE TABLE statement skip the INSERT statements for a specific set of tables?
There is a --no-data option that does this, but it affects all tables AFAIK. So, you'll have to run mysqldump twice.
# Dump all but your_special_tbl
mysqldump --ignore-table=db_name.your_special_tbl db_name > dump.sql
# Dump your_special_tbl without INSERT statements.
mysqldump --no-data db_name your_special_tbl >> dump.sql
You have to call mysqldump twice.
The mysql-stripped-dump script does exactly this.
Hi I use mysql administrator and have restored backup files (backup.sql). I would like to use restore the structure without data and it is not giving me an option to do so. I understand phpadmin provides this. I can not use this however. Any one can tell me an easy way?
Dump database structure only:
cat backup.sql | grep -v ^INSERT | mysql -u $USER -p
This will execute everything in the backup.sql file except the INSERT lines that would have populated the tables. After running this you should have your full table structure along with any stored procedures / views / etc. that were in the original databse, but your tables will all be empty.
You can change the ENGINE to BLACKHOLE in the dump using sed
cat backup.sql | sed 's/ENGINE=(MYISAM|INNODB)/ENGINE=BLACKHOLE/g' > backup2.sql
This engine will just "swallow" the INSERT statements and the tables will remain empty. Of course you must change the ENGINE again using:
ALTER TABLE `mytable` ENGINE=MYISAM;
IIRC the backup.sql files (if created by mysqldump) are just SQL commands in a text file. Just copy-paste all the "create ..." statements from the beginning of the file, but not the "insert" statements in to another file and "mysql < newfile" you should have the empty database without any data in it.
there is no way to tell the mysql client to skip the INSERT commands. the least-hassle way to do this is run the script as-is and let it load the data, then just TRUNCATE all of the tables.
you can write a script to do the following:
1 : import the dump into a new database.
2 : truncate all the tables with a loop.
3 : export the db again.
4 : now u just have the structure
You can backup you MYSQL database structure with
mysqldump -u username –p -d database_name > backup.sql
(You should not supply password at command line as it leads to security risks.MYSQL will ask for password by default.)