Get Overview of MySQL Database Tables
Copy and run summary.sql in MySQL console. Run
call showalltbl("tbl1,tbl2,tbl3");to get a summary of
tbl3etc in your MySQL database (haven’t tried PostgresSQL etc).
Because of how ROR
manages/abstracts database, looking at the database tables, can give
quite some information about the application. For an app that I had
came across, I started with
select count(*) from <tbl1>; followed by
select * from <tbl1> limit 10; for the tables in the database, one
by one. But then I would look at a reference like
would try to recollect what
accounts table looked like. I would
rather have liked to get the above summary for all the tables, copy
them to a text editor and then rearrange and analyze them.
The script below defines procedure
showalltbl to get above mentioned
summary for all the tables, that are passed as comma separated list to
How does this work?
There are three functions defined in the script. The most basic being
execsql. Let me start there. Its job is t take a string, and execute
it as an SQL statement.
Next up is
showtbl. It takes a table name as string. Uses
to select that string (so, the output shows the table name, to
understand which table rest of the summary belongs to). Selects count
on the table. And the show 10 entries from the table.
The last one is
showalltbl, which takes the comma separate string of
tables. Splits them and calls
showtbl on them.
Could have achieved the same result in Ruby. But well. ↩