Many people do not understand the way MySQL licensing, the main reason is that there is no Chinese information no other! I don't want to laugh at anyone, but I think it is necessary to understand this important factor. International lawsuits we've lost too much, I don't want this to be a laughingstock.
Currently, MySQL uses dual authorization (Dual licensed), which is the GPL and MySQL AB developed commercial license agreement. If you use MySQL in a free (open source) project that follows the GPL, you can use MySQL under the GPL protocol. Otherwise, you will need to purchase the commercial license agreement that Mysqlab made. The most important thing here is that you want to use MySQL for free, the software you develop must be free (open source) software that follows the GPL, although there are many free (open source) license agreements that have been approved.
To clarify the scope of authorized jurisdiction
MySQL is a set of client/server (c/s)-structured systems. The dual licensing mechanism binds two large chunks at the same time, but not absolutely. MySQL AB (MySQL's production company) takes into account the convenience of people, the client is fully compliant with the GPL license. That is, in fact MySQL's dual licensing mechanism is a dual feature of the server side. I think I'm going to confuse some people, and the client here refers to the client tool (Mysql.exe) under the command line developed by MySQL AB.
Are there special restrictions under different operating systems?
In the current can say no, if there is only MySQL specific code implementation on the functional differences, the license agreement itself is not a specific distinction. In the early days MySQL did make a specific distinction between Microsoft/non-Microsoft operating systems, and at that point you had to pay to buy the Windows platform's latest MySQL, which is now different.
Are Windows versions restricted?
As has been said before, there is no such distinction, the only difference is the specific implementation of different operating systems caused. Currently, you are free to obtain the latest version of Windows distribution. They are not functional, time limited. Of course, you should follow the license agreement.
Do I need to pay for educational purposes?
In fact, there is no such distinction, the main depends on whether the software is in accordance with the GPL release. Of course, if only used to do classroom teaching is not to buy a commercial license agreement, in which case MySQL follows the GPL license agreement.
How many licenses should I buy?
The license for MySQL is calculated according to the number of computer units, one machine. As for a machine with multiple operating systems, the purchase of several licenses this 龌 鹾 problem don't ask me, I don't know! The relationship between license and technical support?! Technical support and licensing are different things. Although a lot of software will mix them with sales, there should actually be a separate technical support guarantee Agreement signed. I don't know the exact time limit and the price.
Authorization of the MySQL API
The MySQL client API follows the GPL protocol, which contains GNU getopt followed by LGPL, and some local regexp libraries follow the BSD license agreement.
For more information
It is highly recommended to take a look at the relevant licensing section of the MySQL license agreement in the manual, which is written in very detail.