MYSQLDIFF(1) User Contributed Perl Documentation MYSQLDIFF(1)NAMEmysqldiff - compare MySQL database schemas
SYNOPSISmysqldiff [B<options>] B<database1> B<database2>
mysqldiff--help
DESCRIPTIONmysqldiff is a Perl script front-end to the CPAN
<http://www.perl.com/CPAN> module MySQL::Diff
<http://search.cpan.org/search?module=MySQL::Diff> which compares the
data structures (i.e. schema / table definitions) of two MySQL
<http://www.mysql.com/> databases, and returns the differences as a
sequence of MySQL commands suitable for piping into mysql which will
transform the structure of the first database to be identical to that
of the second (c.f. diff and patch).
Database structures can be compared whether they are files containing
table definitions or existing databases, local or remote.
N.B. The program makes no attempt to compare any of the data which may
be stored in the databases. It is purely for comparing the table
definitions. I have no plans to implement data comparison; it is a
complex problem and I have no need of such functionality anyway.
However there is another program coldiff
<http://rossbeyer.net/software/mysql_coldiff/> which does this, and is
based on an older program called datadiff which seems to have vanished
off the 'net.
For PostgreSQL there are similar tools such as pgdiff
<http://pgdiff.sourceforge.net/> and apgdiff
<http://apgdiff.startnet.biz/>.
EXAMPLES
# compare table definitions in two files
mysqldiff db1.mysql db2.mysql
# compare table definitions in a file 'db1.mysql' with a database 'db2'
mysqldiff db1.mysql db2
# interactively upgrade schema of database 'db1' to be like the
# schema described in the file 'db2.mysql'
mysqldiff-A db1 db2.mysql
# compare table definitions in two databases on a remote machine
mysqldiff --host=remote.host.com --user=myaccount db1 db2
# compare table definitions in a local database 'foo' with a
# database 'bar' on a remote machine, when a file foo already
# exists in the current directory
mysqldiff --host2=remote.host.com --password=secret db:foo bar
OPTIONS
More details to come; for now run "mysqldiff --help".
INTERNALS
For both of the database structures being compared, the following
happens:
· If the argument is a valid filename, the file is used to create a
temporary database which "mysqldump -d" is run on to obtain the
table definitions in canonicalised form. The temporary database is
then dropped. (The temporary database is named
"test_mysqldiff_temp_something" because default MySQL permissions
allow anyone to create databases beginning with the prefix
"test_".)
· If the argument is a database, "mysqldump -d" is run directly on
it.
· Where authentication is required, the hostname, username, and
password given by the corresponding options are used (type
"mysqldiff --help" for more information).
· Each set of table definitions is now parsed into tables, and fields
and index keys within those tables; these are compared, and the
differences outputted in the form of MySQL statements.
BUGS, DEVELOPMENT, CONTRIBUTING
See <http://software.adamspiers.org/wiki/mysqldiff>.
COPYRIGHT AND LICENSE
Copyright (c) 2000-2011 Adam Spiers. All rights reserved. This program
is free software; you can redistribute it and/or modify it under the
same terms as Perl itself.
SEE ALSO
MySQL::Diff, MySQL::Diff::Database, MySQL::Diff::Table,
MySQL::Diff::Utils, mysql, mysqldump, mysqlshow
AUTHOR
Adam Spiers <mysqldiff@adamspiers.org>
perl v5.20.2 2015-08-30 MYSQLDIFF(1)
