dbdpp

What is dbdpp?

This is a simple tool to compute differences between two MySQL database tables as a list of SQL commands (INSERT/UPDATE/DELETE) needed to synchronize them. It serves as a faster and simpler replacement for DBDiff.

How to use?

Running the program with no arguments will print its syntax:

USAGE: dbdpp [ source.cnf ] target.cnf source_table_name target_table_name
	(source.cnf and target.cnf should be MySQL-style configuration files)

Example

For example, if source.cnf is

[client]
host=source-database.example.com
user=abc
password=def
database=db_reference

and target.cnf is

[client]
host=target-database.example.com
port=33060
user=abc
password=def
database=db_to_change

running the program as

dbdpp source.cnf target.cnf ref_table target_table > out.sql

will print into out.sql list of SQL statements which should be applied to db_to_change.target_table to make it consistent with db_reference.ref_table. Only INSERT/UPDATE/DELETE statements are generated; there will be no ALTERs, as dbdpp only work for tables with matching structure (the same set of fields and primary keys).

There are two modes of operation:

• if both source.cnf and target.cnf are given (even if they are the same), the tool will fetch all data from both tables and perform comparisons on your local machine;
• if only target.cnf is given, processing will be performed on SQL-level on the database server, and only the differences will be fetched to your local machine.

Choose the option that is better for your particular case performance-wise.

The database names can be entered in the *.cnf files, and/or you may include them in command line arguments as my_db_name.my_table_name. These names will neither be escaped nor quoted, so whatever you pass as a table name will be used as-is both in performed and in generated SQL queries. Therefore, if you do not specify the database name as a prefix for the table name, none will be added to generated INSERT/UPDATE/DELETE queries.

How to compile?

Requirements

To compile dbdpp, CMake build system is recommended. If not available, you can still compile it manually—after all, it’s just a single C++ source file dbdpp.cpp.

Also, both MySQL client development headers as well as MySQL++ headers should be installed. These dependencies can be procured from a default software repository; e.g. in Ubuntu

sudo apt install libmysqlclient-dev libmysql++-dev

Also, you will need a modern C++ compiler with support for C++17 standard.

Unix-family OS

The easiest way is to run

cmake .

followed by

make

in the directory where you cloned your repository; you can also do an out-of-source build, if you prefer. If successful, binary file dbdpp shall appear.

Disclaimer

dbdpp 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; either version 2 of the License, or (at your option) any later version.

dbdpp 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 dbdpp (file “LICENCE”); if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA