When mysqldump is created with --databases or --all-databases option, it will add "CREATE TABLE" and "USE" statements. If you need to restore the dump into different database (different name) you need to remove those statements. For small files it's not a problem - just edit the dump with your favourite text editor. However huge MySQL dumps (e.g. gigabytes big) may be a challenge. Editing with vim means loading the wohle file into the memory - not a good idea.

Solutions:

Filter dump file with grep to ignore CREATE and USE lines on the fly, while restoring:

% egrep -v '^CREATE DATABASE |^USE ' big_mysql_dump.sql | mysql new_dbname

Use hexedit:

% hexedit big_mysql_dump.sql

Edit the file by overwriting CREATE and USE lines with spaces (so file size will not change). In hexedit use TAB to switch to ASCII editing, F2 to save, F10 to exit.

Use mysqldump-filter PHP script to do the same as above.

% git clone https://github.com/tmuras/mysqldump-filter
% cd mysqldump-filter
% ./mysqldump-edit.php -n big_mysql_dump.sql
String to overwrite at position 839:
-->CREATE DATABASE /*!32312 IF NOT EXISTS*/ `phpmyadmin` /*!40100 DEFAULT CHARACTER SET latin1 */;<--

String to overwrite at position 936:
-->USE `phpmyadmin`;<--
% ./mysqldump-edit.php big_mysql_dump.sql
Overwriten line at position 839:
-->CREATE DATABASE /*!32312 IF NOT EXISTS*/ `phpmyadmin` /*!40100 DEFAULT CHARACTER SET latin1 */;<--

Overwriten line at position 936:
-->USE `phpmyadmin`;<--