MySql The service cocould not be started solves The problem of MySql installation. because mySql database needs to be installed today, every time The software is installed, The database is always enough for us, sometimes errors may even cause headaches when installing the system. 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. The first error encountered is You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax. 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. In addition, the login form is always automatically closed in a flash. This is because the MySql server is not started, its command form will be automatically closed when it is started, and the MySql service can be started. 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. After checking MySql, the installation is completed and the re-installation steps are released. The previous versions of the database must be uninstalled. Otherwise, the installation may fail. The following are some notes: unmount in the control panel. The installation directory is not enough for the installation directory to be visible only. In some cases, the system will automatically hide the installation directory. You must first set it in "file organization" to make it visible. Because the hidden files do not notice that when you reinstall the database, the port numbers of each database have been determined. The proportion of Oracle is 1521, and MySql is 3306. If you are prompted that this port is in use, the old database version is not detached. The Registry has many services in the "Administrative Tools" service. These services correspond to the content in the "services" folder in the Registry and need to be manually deleted. You can also press F3 to search for related values and delete all related values. If you have uninstalled the items above, it will usually be okay.