MySQL the service cocould not be started

 

1. Install MySQL
   1. Because MySQL database needs to be installed today, every time the software is installed, the database is always enough for us. Sometimes there are errors or even a proportion of the installed system is a headache.
   2. Today, there are no many errors in the security process. After the restart and re-installation, I finally got stuck. After the installation, I felt like this, what should I do if I uninstall the software or reinstall it later.

1. Minor problems encountered
   1. The first error is you have an error in your SQL syntax; check the manual that corresponds to your MySQL Server version for the right syntax.
      1. According to the problem description, the string syntax entered during connection to the server has some problems. You can check the MySQL database connection characters.
   1. And the login form is always closed automatically in a flash.
      1. This is because the MySQL server is not started, and its command form will be automatically closed when it is started. Just start the MySQL service.
         
      1.  
   1. The second problem is that access is always denied when you connect to the database. It is estimated that the database is not logged on or has insufficient permissions, or the problem occurs halfway through the database creation process. The default root user is not completely created, in this case, you can only reinstall it.
      1. I checked that MySQL was launched because it was half installed during installation.

1. Procedure
   1. The previous versions of the database must be uninstalled. Otherwise, the database cannot be installed successfully. The following are some notes:
      1. Unmount in the control panel.
      1. Installation Directory
         1. It is not enough for the installation directory to only find what you see. Some problems will be automatically hidden by the system. You must first set it in "file organization" to make it visible.
            1. Because the hidden file is not noticed, it is reinstalled once more.
            2. During database installation, the port numbers of each database have been determined. The proportion is Oracle 1521, and MySQL 3306. If the port is already in use, it indicates that the old database has not been uninstalled.
      1. Registry
         1. There are many services in the "Administrative Tools" service, which correspond to the content in the "services" folder in the Registry and need to be manually deleted.
         1. You can also press F3 to search for related values and delete all related values.
   1. If you have uninstalled the items above, it will usually be okay.