it's been a while since i've used a mySQL DB, is it ok to create a new DB table, while the site is active or should i take the site down for maintenance before hand?
-thanks,
Using the CREATE syntax is fine on a live database, just don't run something like DROP or TRUNCATE.
CREATE Syntax
If you're worried about harming your database, take a backup;
mysqldump -u root -p <database_name> > backup.sql
Alternatively, you can create a new user with just the CREATE privilege.
Related
I was working on a site offline. Now, due to some reason, it's not working. I've tried almost everything. To save time, I have setup a fresh mysql and wordpress site.
Now, I have theme files and database folder files like: dp.opt and wp_addonlibrary_addons.frm. How can I properly upload them?
I tried to manually do it, but some error came saying these tables already exist.
Please advice.
I assume your questions is about importing the DB again in MySQL?
Are you still able to export the database from your not working site? Than you could do this (source):
mysqldump --add-drop-table -u user -p > dumpfile.sql
And import it again on your new site with this command:
mysql -u user -p < dumpfile.sql
You won't get the error about already existing tables.
If you can't reach the old database anymore or not able to export, drop the current database first on your new site (make sure you made a backup).
DROP DATABASE databasename
CREATE DATABASE databasename
You can also drop all tables instead of dropping the database. You can use this script: https://www.cyberciti.biz/faq/how-do-i-empty-mysql-database/
Or my preferred method is using PHPMyAdmin to drop all tables.
Then re-import with:
mysql -u user -p < dumpfile.sql
This question already has answers here:
How do I rename a MySQL database (change schema name)?
(46 answers)
Closed 8 years ago.
I created a database with the name of hrms. Now I need to change database name to sunhrm. But, It is disabled in MySQL workbench. Can I do that on the Linux server itself?
In case you need to do that from the command line, just copy, adapt & paste this snippet:
mysql -e "CREATE DATABASE \`new_database\`;"
for table in `mysql -B -N -e "SHOW TABLES;" old_database`
do
mysql -e "RENAME TABLE \`old_database\`.\`$table\` to \`new_database\`.\`$table\`"
done
mysql -e "DROP DATABASE \`old_database\`;"
I don't think you can do this. Basic answers will work in many cases, and in others cause data corruptions. A strategy needs to be chosen based on heuristic analysis of your database. That is the reason this feature was implemented, and then removed. [doc]
You'll need to dump all object types in that database, create the newly named one and then import the dump. If this is a live system you'll need to take it down. If you cannot, then you will need to setup replication from this database to the new one.
If you want to see the commands that could do this, #satishD has the details, which conveys some of the challenges around which you'll need to build a strategy that matches your target database.
It's possible to copy database via mysqldump command without storing dump into file:
mysql -u root -p -e "create database my_new_database"
mysqldump -u root -p original_database | mysql -u root -p my_new_database
mysql -u root -p -e "drop database original_database"
You can create a new database exactly as the previous database existed and then drop the old database when you're done. Use the mysqldump tool to create a .sql backup of the database via mysqldump orig_db > orig_db.sql or if you need to use a username and password then run mysqldump -u root -p orig_db > orig_db.sql. orig_db is the name of the database you want to "rename", root would be the user you're logging in as and orig_db.sql would be the file created containing the backup. Now create a new, empty database with the name you want for the database. For example, mysql -u root -p -e "create database new_db". Once that's done, then run mysql -u root -p new_db < orig_db.sql. new_db now exists as a perfect copy of orig_db. You can then drop the original database as you now have it existing in the new database with the database name you wanted.
The short, quick steps without all the above explanation are:
mysqldump -u root -p original_database > original_database.sql
mysql -u root -p -e "create database my_new_database"
mysql -u root -p my_new_database < original_database.sql
mysql -u root -p -e drop database originl_database
Hope this helps and this is a reliable means to accomplish it without using some ad-hoc method that will corrupt your data and create inconsistencies.
You can do it by RENAME statement for each table in your "current_db" after create the new schema "other_db"
RENAME TABLE current_db.tbl_name TO other_db.tbl_name
Source Rename Table Syntax
In short no. It is generally thought to be too dangerous to rename a database. MySQL had that feature for a bit, but it was removed. You would be better off using the workbench to export both the schema and data to SQL then changing the CREATE DATABASE name there before you run/import it.
I used following method to rename the database
take backup of the file using mysqldump or any DB tool eg heidiSQL,mysql administrator etc
Open back up (eg backupfile.sql) file in some text editor.
Search and replace the database name and save file.
Restore the edited SQL file
If your DB contains only MyISAM tables (do not use this method if you have InnoDB tables):
shut down the MySQL server
go to the mysql data directory and rename the database directory (Note: non-alpha characters need to be encoded in a special way)
restart the server
adjust privileges if needed (grant access to the new DB name)
You can script it all in one command so that downtime is just a second or two.
For impatient mysql users (like me), the solution is:
/etc/init.d/mysql stop
mv /var/lib/mysql/old_database /var/lib/mysql/new_database
/etc/init.d/mysql start
First backup the old database called HRMS and edit the script file with replace the word HRMS to SUNHRM. After this step import the database file to the mysql
Another way to rename the database or taking image of the database is by using Reverse engineering option in the database tab. It will create a ERR diagram for the database. Rename the schema there.
after that go to file menu and go to export and forward engineer the database.
Then you can import the database.
mysql> -u username -p [database] < file.sql
restores database. I do not have a create clause in my dumped file, hence I need to create a database and then restore. I can do this to create.
mysql> create database [database];
Fair enough. Now how can I achieve the above restoration in one line? Is there anyway to restore a database by creating the database before that with a single line of code?
I can certainly live without it, but would be nice to know.. Thanks..
(echo "create database XYZ; use XYZ;"; cat file.sql) | mysql -u username -p
could do the trick.
I am trying to do some maintenance on MySQL database data and I created a dump file with the backed up current database.
I want to restore all that data into another database called something like original_db_name_test
Is there a command for that?
This depends on how you invoked mysqldump
If you used mysqldump dbname, then your dump contains neither CREATE DATABASE nor USE DATABASE.
Just create the database with the new name and feed the dump to mysql -D new_dbname.
If you used mysqldump --database dbname, then the dump contains CREATE DATABASE and USE DATABASE statements.
You need to comment them out or replace with new_dbname.
mysql -u usernamehere -p original_db_name_test < yourdumpfilehere.sql
If you used mysqldump to create the dump file, simply:
Create a new database (use the mysqladmin command line tool - "mysqladmin create [new database name]").
Edit the dump file to add a "USE [new database name];" at the top. (There might be an existing use statement that's commented out, so you can change this and un-comment it.)
Import the dump into the new table via "mysql -u <user name> -p < [dump file name]".
Incidentally, when creating a dump via mysqldump, I'd be tempted to use the "--add-drop-table" option, as this will cull any existing table with the same name prior to issuing the table creation statement.
you can use the 'MySQL Workbench' Application and do this with a nice gui
I have a mysql dump created with mysqldump that holds all the tables in my database and all their data. However I only want to restore two tables. (lets call them kittens and kittens_votes)
How would I restore those two tables without restoring the entire database?
Well, you have three main options.
You can manually find the SQL statements in the file relating to the backed up tables and copy them manually. This has the advantage of being simple, but for large backups it's impractical.
Restore the database to a temporary database. Basically, create a new db, restore it to that db, and then copy the data from there to the old one. This will work well only if you're doing single database backups (If there's no CREATE DATABASE command(s) in the backup file).
Restore the database to a new database server, and copy from there. This works well if you take full server backups as opposed to single database backups.
Which one you choose will depend upon the exact situation (including how much data you have)...
You can parse out CREATE TABLE kittens|kitten_votes AND INSERT INTO ... using regexp, for example, and only execute these statements. As far as I know, there's no other way to "partially restore" from dump.
Open the .sql file and copy the insert statements for the tables you want.
create a new user with access to only those 2 tables. Now restore the DB with -f (force) option that will ignore the failed statements and execute only those statements it has permission to.
What you want is a "Single Table Restore"
http://hashmysql.org/wiki/Single_table_restore
A few options are outlined above ... However the one which worked for me was:
Create a new DB
$ mysql -u root -p CREATE DATABASE temp_db
Insert the .sql file ( the one with the desired table ) into the new DB
$ mysql -u root -p temp_db < ~/full/path/to/your_database_file.sql
dump the desired table
$ mysqldump -u root -p temp_db awesome_single_table > ~/awesome_single_table.sql
import desired table
$ mysql -u root -p original_database < ~/awesome_single_table.sql
Then delete the temp_db and you're all golden!