Compare two MySQL databases [closed]

Answer 1

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Answer 2

dbSolo, it is paid but this feature might be the one you are looking for http://www.dbsolo.com/help/compare.html

It works with Oracle, Microsoft SQL Server, Sybase, DB2, Solid, PostgreSQL, H2 and MySQL

Answer 3

Very easy to use comparison and sync tool:
Database Comparer http://www.clevercomponents.com/products/dbcomparer/index.asp

Advantages:

• fast
• easy to use
• easy to select changes to apply

Disadvantages:

• does not sync length to tiny ints
• does not sync index names properly
• does not sync comments

Answer 4

If you only need to compare schemas (not data), and have access to Perl, mysqldiff might work. I've used it because it lets you compare local databases to remote databases (via SSH), so you don't need to bother dumping any data.

http://adamspiers.org/computing/mysqldiff/

It will attempt to generate SQL queries to synchronize two databases, but I don't trust it (or any tool, actually). As far as I know, there's no 100% reliable way to reverse-engineer the changes needed to convert one database schema to another, especially when multiple changes have been made.

For example, if you change only a column's type, an automated tool can easily guess how to recreate that. But if you also move the column, rename it, and add or remove other columns, the best any software package can do is guess at what probably happened. And you may end up losing data.

I'd suggest keeping track of any schema changes you make to the development server, then running those statements by hand on the live server (or rolling them into an upgrade script or migration). It's more tedious, but it'll keep your data safe. And by the time you start allowing end users access to your site, are you really going to be making constant heavy database changes?

Answer 5

There are many ways certainly, but in my case I prefer the dump and diff command. So here is an script based on Jared's comment:

#!/bin/sh

echo "Usage: dbdiff [user1:pass1@dbname1] [user2:pass2@dbname2] [ignore_table1:ignore_table2...]"

dump () {
  up=${1%%@*}; user=${up%%:*}; pass=${up##*:}; dbname=${1##*@};
  mysqldump --opt --compact --skip-extended-insert -u $user -p$pass $dbname $table > $2
}

rm -f /tmp/db.diff

# Compare
up=${1%%@*}; user=${up%%:*}; pass=${up##*:}; dbname=${1##*@};
for table in `mysql -u $user -p$pass $dbname -N -e "show tables" --batch`; do
  if [ "`echo $3 | grep $table`" = "" ]; then
    echo "Comparing '$table'..."
    dump $1 /tmp/file1.sql
    dump $2 /tmp/file2.sql
    diff -up /tmp/file1.sql /tmp/file2.sql >> /tmp/db.diff
  else
    echo "Ignored '$table'..."
  fi
done
less /tmp/db.diff
rm -f /tmp/file1.sql /tmp/file2.sql

Feedback is welcome :)

Answer 6

There is a useful tool written using perl called Maatkit. It has several database comparison and syncing tools among other things.