Limiting the number of records from mysqldump?

As skaffman says, use the --where option:

mysqldump --opt --where="1 limit 1000000" database

Of course, that would give you the first million rows from every table.

If you want to get n records from a specific table you can do something like this:

mysqldump --opt --where="1 limit 1000000" database table > dump.sql

This will dump the first 1000000 rows from the table named table into the file dump.sql.

As the default order is ASC which is rarely what you want in this situation, you need to have a proper database design to make DESC work out of the box. If all your tables have ONE primary key column with the same name (natural or surrogate) you can easily dump the n latest records using:

mysqldump --opt --where="1 ORDER BY id DESC limit 1000000" --all-databases > dump.sql

This is a perfect reason to why you should always name your PK's id and avoid composite PK's, even in association tables (use surrogate keys instead).