Drop multiple databases with names matching a pattern

Question

I want to drop all the databases starting with a word.

abc
xyz
cms_db1
cms_db2
cms_xyz
pqr

In the example given above, I will like to drop all

Answer 1

Improvising on the excellent answer by @cloakedninjas, for easier retrieval of all the queries to execute in a single string.

Firstly, you can set the maximum value for group_concat_max_len to the maximum possible value, for this particular session:

SET SESSION group_concat_max_len = @@max_allowed_packet;

Now, you can prepare a query string (to execute later) using SQL. Using information_schema, we can get name of all the databases matching the pattern. Now, use Concat() to prepare a single DROP DATABASE .. query, and then utilize Group_Concat() to merge them all into a single string, for easier retrieval.

SELECT GROUP_CONCAT(CONCAT('DROP DATABASE `', SCHEMA_NAME, '`;') 
                    SEPARATOR ' ') AS query_to_execute
FROM information_schema.SCHEMATA
WHERE SCHEMA_NAME LIKE 'cms_%'

Now copy the string in query_to_execute and run it separately.