A MySQL script that will generate a list of statements to drop all DBs on a server.

create_drop_all_dbs.sql

-- Run this script
SELECT CONCAT('DROP DATABASE `', schema_name, '`;') AS stmt
FROM information_schema.schemata
WHERE schema_name NOT IN ('information_schema', 'performance_schema', 'mysql')
ORDER BY SCHEMA_NAME;

-- Copy the output into your clipboard

SET FOREIGN_KEY_CHECKS = 0;

-- Paste from the clipboard and run the "drop" set

SET FOREIGN_KEY_CHECKS = 1;

-- USE WITH CAUTION

-- CREDIT: http://stackoverflow.com/a/18279731/632985