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 utility
       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 executed 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. Objects not
       appearing in either database produce an error.

       To compare a specific pair of objects, add an object name to each
       database name using the db.obj format. For example, use the
       db1.obj1:db2.obj2 format 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 formats.

       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 utility 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 the diff styled output, use one of the
       following values with the --difftype option:

       o   unified (default)

           Display unified format output.

       o   context

           Display context format output.

       o   differ

           Display differ-style format output.

       o   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:

           shell> 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: Produces output that shows how to make the
           definitions of objects on server1 like the definitions of the
           corresponding objects on server2.

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

       The default direction is server1.

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

       The utility stops at 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.PP mysqldiff accepts the following command-line
       options:

       o   --help

           Display a help message and exit.

       o   --license

           Display license information and exit.

       o   --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.

       o   --character-set=<charset>

           Sets the client character set. The default is retrieved from the
           server variable character_set_client.

       o   --difftype=<difftype>, -d<difftype>

           Specify the difference display format. Permitted format values are
           unified (default), context, differ, and sql.

       o   --compact

           Compacts the output by reducing the control lines that are
           displayed in the diff results. This option should be used together
           with one of the following difference types: unified or context.

       o   --force

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

       o   --quiet, -q

           Do not print anything. Return only an exit code of success or
           failure.

       o   --server1=<source>

           Connection information for the first server.

           To connect to a server, it is necessary to specify connection
           parameters such as user name, host name, password, and either a
           port or socket. MySQL Utilities provides a number of ways to
           provide this information. All of the methods require specifying
           your choice via a command-line option such as --server, --master,
           --slave, etc. The methods include the following in order of most
           secure to least secure.

           o   Use login-paths from your .mylogin.cnf file (encrypted, not
               visible). Example : <login-path>[:<port>][:<socket>]

           o   Use a configuration file (unencrypted, not visible) Note:
               available in release-1.5.0. Example :
               <configuration-file-path>[:<section>]

           o   Specify the data on the command-line (unencrypted, visible).
               Example : <user>[:<passwd>]@<host>[:<port>][:<socket>]


       o   --server2=<source>

           Connection information for the second server.

           To connect to a server, it is necessary to specify connection
           parameters such as user name, host name, password, and either a
           port or socket. MySQL Utilities provides a number of ways to
           provide this information. All of the methods require specifying
           your choice via a command-line option such as --server, --master,
           --slave, etc. The methods include the following in order of most
           secure to least secure.

           o   Use login-paths from your .mylogin.cnf file (encrypted, not
               visible). Example : <login-path>[:<port>][:<socket>]

           o   Use a configuration file (unencrypted, not visible) Note:
               available in release-1.5.0. Example :
               <configuration-file-path>[:<section>]

           o   Specify the data on the command-line (unencrypted, visible).
               Example : <user>[:<passwd>]@<host>[:<port>][:<socket>]


       o   --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.

       o   --skip-table-options

           Ignore the differences between all table options, such as
           AUTO_INCREMENT, ENGINE, CHARSET, etc.). A warning is issued if the
           --skip-table-options option is used and table option differences
           are found.

       o   --ssl-ca

           The path to a file that contains a list of trusted SSL CAs.

       o   --ssl-cert

           The name of the SSL certificate file to use for establishing a
           secure connection.

       o   --ssl-cert

           The name of the SSL key file to use for establishing a secure
           connection.

       o   --ssl

           Specifies if the server connection requires use of SSL. If an
           encrypted connection cannot be established, the connection attempt
           fails. Default setting is 0 (SSL not required).

       o   --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.

       o   --version

           Display version information and exit.

       o   --width=<number>

           Change the display width of the test report. The default is 75
           characters.
       NOTES.PP 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.

       The path to the MySQL client tools should be included in the PATH
       environment variable in order to use the authentication mechanism with
       login-paths. This will allow the utility to use the my_print_defaults
       tools which is required to read the login-path values from the login
       configuration file (.mylogin.cnf).

       If any database object identifier specified as an argument contains
       special characters or is a reserved word, then it must be appropriately
       quoted with backticks (`). In turn, names quoted with backticks must
       also be quoted with single or double quotes depending on the operating
       system, i.e. (") in Windows or (') in non-Windows systems, in order for
       the utilities to read backtick quoted identifiers as a single argument.
       For example, to show the difference between table weird`table1 from
       database weird`db.name and table weird`table2 from database
       other:weird`db.name, the objects pair must be specified using the
       following syntax (in non-Windows):
       '`weird``db.name`.`weird``table1`:`other:weird``db.name`.`weird``table2`'.
       EXAMPLES.PP To compare the employees and emp databases on the local
       server, use this command:

           shell> 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.
           shell> 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.
           shell> 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:

           shell> 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 statements:
           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:

           shell> 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 statements:
           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:

           shell> 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 statements:
           # --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.

       PERMISSIONS REQUIRED.PP The user must have SELECT privileges for both
       objects on both servers as well as SELECT on the mysql database.

COPYRIGHT
       Copyright (C) 2006, 2015, Oracle and/or its affiliates. All rights
       reserved.

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

       This documentation is distributed in the hope that it will be useful,
       but WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY 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 the program; if not, write to the Free Software Foundation, Inc.,
       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
       http://www.gnu.org/licenses/.


SEE ALSO
       For more information, please refer to the MySQL Utilities and Fabric
       documentation, which is available online at
       http://dev.mysql.com/doc/index-utils-fabric.html

AUTHOR
       Oracle Corporation (http://dev.mysql.com/).



MySQL 1.5.6                       09/15/2015                      MYSQLDIFF(1)
