MYSQLDIFF(1)							  MySQL Utilities						      MYSQLDIFF(1)

NAME

       mysqldiff - Identify differences among database objects

SYNOPSIS

       mysqldiff [options] {db1[:db1] | db1.obj1[:db2.obj2]} ...

DESCRIPTION

       This  utility reads the definitions of objects and compares them using a diff-like method to determine whether they are the same. The util-
       ity displays the differences for objects that are not the same.

       Use the notation db1:db2 to name two databases to compare, or, alternatively just db1 to compare two databases with  the  same  name.   The
       latter case is a convenience notation for comparing same-named databases on different servers.

       The comparison may be run against two databases of different names on a single server by specifying only the --server1 option. The user can
       also connect to another server by specifying the --server2 option. In this case, db1 is taken from server1 and db2 from server2.

       When a database pair is specified, all objects in one database are compared to the corresponding objects in  the  other.  Any  objects  not
       appearing in either database produce an error.

       To  compare  a  specific  pair of objects, add an object name to each database name in db.obj format. For example, use db1.obj1:db2.obj2 to
       compare two named objects, or db1.obj1 to compare an object with the same name in databases with the same name. It is not legal	to  mix  a
       database name with an object name. For example, db1.obj1:db2 and db1:db2.obj2 are illegal.

       The  comparison may be run against a single server for comparing two databases of different names on the same server by specifying only the
       --server1 option. Alternatively, you can also connect to another server by specifying the --server2 option. In this case, the first  object
       to compare is taken from server1 and the second from server2.

       By  default,  the  utilty generates object differences as a difference report. However, you can generate a transformation report containing
       SQL statements for transforming the objects for conformity instead.  Use the 'sql' value for the --difftype option  to  produce	a  listing
       that  contains  the appropriate ALTER commands to conform the object definitions for the object pairs specified. If a transformation cannot
       be formed, the utility reports the diff of the object along with a warning statement. See important limitations in the NOTES section.

       To specify how to display diff-style output, use one of the following values with the --difftype option:

       unified (default)
	      Display unified format output.

       context
	      Display context format output.

       differ Display differ-style format output.

       sql    Display SQL transformation statement output.

       The --changes-for option controls the direction of the difference (by specifying the object to be transformed)  in  either  the	difference
       report (default) or the transformation report (designated with the --difftype=sql option). Consider the following command:

       mysqldiff --server1=root@host1 --server2=root@host2 --difftype=sql 
	 db1.table1:dbx.table3

       The  leftmost  database	(db1) exists on the server designated by the --server1 option (host1).	The rightmost database (dbx) exists on the
       server designated by the --server2 option (host2).

       o --changes-for=server1: Produce output that shows how to make the definitions of objects on server1 like the  definitions  of  the  corre-
	 sponding objects on server2.

       o --changes-for=server2:  Produce  output  that	shows how to make the definitions of objects on server2 like the definitions of the corre-
	 sponding objects on server1.

       The default direction is server1.

       For sql difference format, you can also see the reverse transformation by specifying the --show-reverse option.

       The utility stops on the first occurrence of missing objects or when an object does not match.  To  override  this  behavior,  specify  the
       --force option to cause the utility to attempt to compare all objects listed as arguments.

OPTIONS

       mysqldiff accepts the following command-line options:

       --help Display a help message and exit.

       --changes-for=<direction>
	      Specify the server to show transformations to match the other server. For example, to see the transformation for transforming object
	      definitions on server1 to match the corresponding definitions on server2, use --changes-for=server1. Permitted  values  are  server1
	      and server2. The default is server1.

       --difftype=<difftype>, -d<difftype>
	      Specify the difference display format. Permitted format values are unified, context, differ, and sql. The default is unified.

       --force
	      Do not halt at the first difference found. Process all objects to find all differences.

       --quiet, -q
	      Do not print anything. Return only an exit code of success or failure.

       --server1=<source>
	      Connection information for the first server in <user>[:<passwd>]@<host>[:<port>][:<socket>] format.

       --server2=<source>
	      Connection information for the second server in <user>[:<passwd>]@<host>[:<port>][:<socket>] format.

       --show-reverse
	      Produce  a  transformation report containing the SQL statements to conform the object definitions specified in reverse. For example,
	      if --changes-for is set to server1, also generate the transformation for server2. Note: The reverse changes are annotated and marked
	      as comments.

       --verbose, -v
	      Specify  how  much  information to display. Use this option multiple times to increase the amount of information.  For example, -v =
	      verbose, -vv = more verbose, -vvv = debug.

       --version
	      Display version information and exit.

       --width=<number>
	      Change the display width of the test report.  The default is 75 characters.

NOTES

       You must provide connection parameters (user, host, password, and so forth) for an account that has the appropriate  privileges	to  access
       all objects to be compared.

       The SQL transformation feature has these known limitations:

       o When  tables with partition differences are encountered, the utility generates the ALTER TABLE statement for all other changes but prints
	 a warning and omits the partition differences.

       o If the transformation detects table options in the source table (specified with the --changes-for option) that are not changed or do  not
	 exist in the target table, the utility generates the ALTER TABLE statement for all other changes but prints a warning and omits the table
	 option differences.

       o Rename for events is not supported. This is because mysqldiff compares objects by name. In this case, depending on the direction  of  the
	 diff, the event is identified as needing to be added or a DROP EVENT statement is generated.

       o Changes in the definer clause for events are not supported.

       o SQL extensions specific to MySQL Cluster are not supported.

       For the --difftype option, the permitted values are not case sensitive. In addition, values may be specified as any unambiguous prefix of a
       valid value. For example, --difftype=d specifies the differ type. An error occurs if a prefix matches more than one valid value.

EXAMPLES

       To compare the employees and emp databases on the local server, use this command:

       $ mysqldiff --server1=root@localhost employees:emp1
       # server1 on localhost: ... connected.
       WARNING: Objects in server1:employees but not in server2:emp1:
	 EVENT: e1
       Compare failed. One or more differences found.

       $ mysqldiff --server1=root@localhost 
		  employees.t1:emp1.t1 employees.t3:emp1.t3
       # server1 on localhost: ... connected.
       # Comparing employees.t1 to emp1.t1				  [PASS]
       # server1 on localhost: ... connected.
       # Comparing employees.t3 to emp1.t3				  [PASS]
       Success. All objects are the same.

       $ mysqldiff --server1=root@localhost 
		employees.salaries:emp1.salaries --differ
       # server1 on localhost: ... connected.
       # Comparing employees.salaries to emp1.salaries			  [FAIL]
       # Object definitions are not the same:
	 CREATE TABLE `salaries` (
	   `emp_no` int(11) NOT NULL,
	   `salary` int(11) NOT NULL,
	   `from_date` date NOT NULL,
	   `to_date` date NOT NULL,
	   PRIMARY KEY (`emp_no`,`from_date`),
	   KEY `emp_no` (`emp_no`)
       - ) ENGINE=InnoDB DEFAULT CHARSET=latin1
       ?	   ^^^^^
       + ) ENGINE=MyISAM DEFAULT CHARSET=latin1
       ?	  ++ ^^^
       Compare failed. One or more differences found.

       The following examples show how to generate a transformation report. Assume the following object definitions:

       Host1:

       CREATE TABLE db1.table1 (num int, misc char(30));

       Host2:

       CREATE TABLE dbx.table3 (num int, notes char(30), misc char(55));

       To generate a set of SQL statements that transform the definition of db1.table1 to dbx.table3, use this command:

       $ mysqldiff --server1=root@host1 --server2=root@host2 
	     --changes-for=server1 --difftype=sql 
	     db1.table1:dbx.table3
       # server1 on host1: ... connected.
       # server2 on host2: ... connected.
       # Comparing db1.table1 to dbx.table3				  [FAIL]
       # Transformation statments:

       ALTER TABLE db1.table1
	 ADD COLUMN notes char(30) AFTER a,
	 CHANGE COLUMN misc misc char(55);

       Compare failed. One or more differences found.

       To generate a set of SQL statements that transform the definition of dbx.table3 to db1.table1, use this command:

       $ mysqldiff --server1=root@host1 --server2=root@host2 
	     --changes-for=server2 --difftype=sql 
	     db1.table1:dbx.table3
       # server1 on host1: ... connected.
       # server2 on host2: ... connected.
       # Comparing db1.table1 to dbx.table3				  [FAIL]
       # Transformation statments:

       ALTER TABLE dbx.table3
	 DROP COLUMN notes,
	 CHANGE COLUMN misc misc char(30);

       Compare failed. One or more differences found.

       To generate a set of SQL statements that transform the definitions of dbx.table3 and db1.table1 in both directions, use this command:

       $ mysqldiff --server1=root@host1 --server2=root@host2 
	     --show-reverse --difftype=sql 
	     db1.table1:dbx.table3
       # server1 on host1: ... connected.
       # server2 on host2: ... connected.
       # Comparing db1.table1 to dbx.table3				  [FAIL]
       # Transformation statments:

       # --destination=server1:
       ALTER TABLE db1.table1
	 ADD COLUMN notes char(30) AFTER a,
	 CHANGE COLUMN misc misc char(55);

       # --destination=server2:
       # ALTER TABLE dbx.table3
       #   DROP COLUMN notes,
       #   CHANGE COLUMN misc misc char(30);

       Compare failed. One or more differences found.

COPYRIGHT

       Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as  published	by
       the Free Software Foundation; version 2 of the License.

       This  program  is  distributed  in  the	hope  that  it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MER-
       CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with this program; if not, write to the Free  Software  Foundation,
       Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

AUTHOR

       MySQL Utilities Team

COPYRIGHT

       2010, Oracle and/or its affiliates. All rights reserved.

1.0.3								   May 09, 2012 						      MYSQLDIFF(1)