Recently I have dumped some data from a magento theme into mysql, I want to undump or remove that from mysql database and want to restore the previous database.
check the tables used in dump.sql after unzipping the archive file. drop the tables that were created while installing the theme.
To check which tables were created, check create table statement in your dump.sql. After that delete data from other tables which were not created by your theme.
Make sure you don't delete the entire table, use proper where clauses. If you need any more assistance, please post your dump.sql.
PS: Though I am not too sure if SO would allow large portion of code, though try it out.
Related
I'm wondering if there is any better way than going through the tables one by one adding the columns missing when some fields/tables needs to be added because of the most recent changes in the app?
For example, I'm working at the localhost and when I finish doing the new version of my app, I will put all the files into my FTP and, sometimes, I have done, in my local database, changes and so it means that I also need to update my database at my server.
There's any better way to add/edit the columns/tables without changing the info? Some of the columns are also deleted, etc.
Hopefully you've thought your database design through so that making changes to the structure is a rare occurrence. If you're making regular changes to the number of columns or adding tables, it's likely a sign that you haven't normalized your database structure sufficiently.
Anyway, I'd script it as an SQL file that you deploy (which you can then run through phpMyAdmin or the command line or any other means you prefer to execute SQL queries). This has the added advantage of being something you can easily duplicate across your development and production databases, send to customers, and if you wish store in version control so you know when exactly you made the changes to the database.
This way, you'll end up with an SQL file that has a couple of statements like
ALTER TABLE `foo` ADD `new` INT NOT NULL ;
or something similar.
As for how you'd make the file, probably the easiest way is just copying and pasting the generated SQL statement from phpMyAdmin after modifying the table -- the SQL code used to make the change is shown near the top of the screen on the next page. You can copy and paste that to a new text file to create your SQL file. You may wish to add the first line
use `baz`;
using your database name instead of "baz". That way you don't have to specify on import which database the changes are meant for.
Hope this helps.
I had made two database with exactly same tables and columns say A and B in mysql. I created dump of database A and then try to update contents of DataBase B using dump of DataBase A. I was using command -->source [path]; ./ What it did that dump of DataBase A completely removed the contents of DataBase B. I was not able figure out how to update one database using dump of another database. Please help me.
You can do this through replication. go through these useful links First link
Second link
Just some pointers here.
I am making fairly extensive modifications to a site, including the MySQL database.
My plan is to do everything on my development server, export the new MySQL structure for the db and import it onto the clients server.
Basically I need to know that performing a structure only import will not overwrite/delete existing data. I am not making changes to the data type or field length.
In my experience, when you export a database (through phpMyAdmin for instance), part of the SQL script that is created includes a "DROP TABLE IF EXISTS 'table_name';" before doing a "CREATE TABLE 'table_name'...;" to build the new table.
My guess is that this is not what you want to do! Certainly use the dev system to alter the structure in order to make everything correct, but then look around for a database synchronisation routine where you can provide the old structure, the new structure, and the software will create the appropriate "ALTER TABLE 'table_name'...;" scripts to make the required changes.
You should then really examine these change files before executing them on the live database, and of course BACKUP the live database, and ensure you are able to fully recover from the backup before starting any of the alterations!
I've had to do this a lot, and it always goes like this:
Make a backup of the live database, complete with data.
Make a backup of the live database schema only.
Calculate the differences between the old (live) schema and the new (devel) schema.
Create all of the 'ALTER TABLE ...' DDL statements necessary to upgrade from the old schema to the new one. Keep in mind that if you rename a field, you probably won't be able to just rename it -- you'll need to create the new field, copy the data from the old field, and then drop the old field.
If you changed relationships between tables, you'll probably need to drop indexes and foreign key relationships first, and then add them back afterwards.
You'll need to populate any new fields based upon their default values, if any.
Once you've got all the pieces working, you'll need to combine them into one large script, and then run it on a copy of the live database.
Dump the schema and compare it against the desired new schema -- if they don't match, go back to step 3 and repeat.
Dump the data and compare it against the expected changes -- again, if they don't match, go back to step 3 and repeat.
You're going to learn a lot more about SQL DDL/DML during this process than you ever thought you'd learn. (For one project, where we were switching from natural keys to UUID keys for 50+ tables, I ended up writing programs to generate all of the DDL/DML.)
Good luck, and make frequent backups.
I'd recommend to prepare a sql script for every change you do on development server, so you will be able to reproduce it on development. You shouldn't get to the point where you need to calculate differences between database structures
This is how I do it, all changes are reflected in sql scripts, and I can reconstruct the history of my database running all these files if needed.
Test the final release version on a "staging" mysql server. Make a copy of your production server on another machine and test your script to make sure everything's ok.
Of course, preliminary database backup is a must.
If I have a MySQL database with several tables on a live server, now I would like to migrate this database to another server. Of course, the migration I mean here involves some database tables, for example: add some new columns to several tables, add some new tables etc..
Now, the only method I can think of is to use some php/python(two scripts I know) script, connect two databases, dump the data from the old database, and then write into the new database. However, this method is not efficient at all. For example: in old database, table A has 28 columns; in new database, table A has 29 columns, but the extra column will have default value 0 for all the old rows. My script still needs to dump the data row by row and insert each row into the new database.
Using MySQLDump etc.. won't work. Here is the detail. For example: I have FOUR old databases, I can name them as 'DB_a', 'DB_b', 'DB_c', 'DB_d'. Now the old table A has 28 columns, I want to add each row in table A into the new database with a new column ID 'DB_x' (x to indicate which database it comes from). If I can't differentiate the database ID by the row's content, the only way I can identify them is going through some user input parameters.
Is there any tools or a better method than writing a script yourself? Here, I dont need to worry about multithread writing problems etc.., I mean the old database will be down (not open to public usage etc.., only for upgrade ) for a while.
Thanks!!
I don't entirely understand your situation with the columns (wouldn't it be more sensible to add any new columns after migration?), but one of the arguably fastest methods to copy a database across servers is mysqlhotcopy. It can copy myISAM only and has a number of other requirements, but it's awfully fast because it skips the create dump / import dump step completely.
Generally when you migrate a database to new servers, you don't apply a bunch of schema changes at the same time, for the reasons that you're running into right now.
MySQL has a dump tool called mysqldump that can be used to easily take a snapshot/backup of a database. The snapshot can then be copied to a new server and installed.
You should figure out all the changes that have been done to your "new" database, and write out a script of all the SQL commands needed to "upgrade" the old database to the new version that you're using (e.g. ALTER TABLE a ADD COLUMN x, etc). After you're sure it's working, take a dump of the old one, copy it over, install it, and then apply your change script.
Use mysqldump to dump the data, then echo output.txt > msyql. Now the old data is on the new server. Manipulate as necessary.
Sure there are tools that can help you achieving what you're trying to do. Mysqldump is a premier example of such tools. Just take a glance here:
http://dev.mysql.com/doc/refman/5.1/en/mysqldump.html
What you could do is:
1) You make a dump of the current db, using mysqldump (with the --no-data option) to fetch the schema only
2) You alter the schema you have dumped, adding new columns
3) You create your new schema (mysql < dump.sql - just google for mysql backup restore for more help on the syntax)
4) Dump your data using the mysqldump complete-insert option (see link above)
5) Import your data, using mysql < data.sql
This should do the job for you, good luck!
Adding extra rows can be done on a live database:
ALTER TABLE [table-name] ADD [row-name] MEDIUMINT(8) default 0;
MySql will default all existing rows to the default value.
So here is what I would do:
make a copy of you're old database with MySql dump command.
run the resulting SQL file against you're new database, now you have an exact copy.
write a migration.sql file that will modify you're database with modify table commands and for complex conversions some temporary MySql procedures.
test you're script (when fail, go to (2)).
If all OK, then goto (1) and go live with you're new database.
These are all valid approaches, but I believe you want to write a sql statement that writes other insert statements that support the new columns you have.
Hi I need to backup MySQL database and then deploy it on another MySQL server.
The problem is, I need it backup without data , just script which creates database, tables, procedures, users, resets autoincrements etc. ...
I tried MySQL administrator tool (Windows) and UNchecked "complete inserts check box", but it still created it ...
Thanks in advance
use mysqldump with option -d or --no-data
don't forget option -R to get the procedures
this page could help you: http://dev.mysql.com/doc/refman/5.0/en/mysqldump.html
From within phpMyAdmin you can export the structure, with or without the data. The only thing I'm not sure of, is wether it exports users as well. If you like, I can test that tomorrow morning. It exports users too. You can check all sorts of options.
(source: obviousmatter.com)
According to the page, there isn't a good way to dump the routines and have them easily able to be recreated.
What they suggest is to dump the mysql.proc table directly. Including all the data.
Then use your myback.sql to restore the structure. Then restore the mysql.proc table with all of its data.
"... If you require routines to be re-created with their original timestamp attributes, do not use --routines. Instead, dump and reload the contents of the mysql.proc table directly, using a MySQL account that has appropriate privileges for the mysql database. ..."