Total number of fields in all tables in database

Question

I have a huge database with hundreds of tables and I want to find out the total fields (columns) defined in all of the tables.

Is there a sql query that can give me that? If not, what would be the best way?

Answer 1

Is this what you want?

select count(*)
from information_schema.columns
where table_schema = 'your_schema'

You can run it like this to see if it is reasonable:

select table_name, column_name
from information_schema.columns
where table_schema = 'your_schema'
order by 1, 2

Answer 2

Try this (while logged into your current schema):

select count(*) from information_schema.columns where table_schema = DATABASE();

Answer 3

I am new in mysql but if table information_schema.columns is the table with table_name and column_name information then you can use following query

select table_name, count( distinct column_name ) column_number_used
from information_schema.columns 
where table_schema = 'your_schema' 
group by table_name

this should give all table names with respective column number used in that table..