Kettle是使用Java开发，开源的一款ETL工具，这里记录一下关于Kettle有关于数据库连接的问题
1、mysql版本需要注意区分，在mysql8.0的文档中官方已经给出，使用caching_sha2_password作为首选身份验证插件，
同时，官方也给出解决方案
kettle连接数据库问题及解决方法：
1、错误连接数据库 [111] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database
Driver class 'org.gjt.mm.mysql.Driver' could not be found, make sure the 'MySQL' driver (jar file) is installed.
org.gjt.mm.mysql.Driver
org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database
Driver class 'org.gjt.mm.mysql.Driver' could not be found, make sure the 'MySQL' driver (jar file) is installed.
org.gjt.mm.mysql.Driver
解决方案：这样的报错是因为缺少连接数据库的jar包，在mysql官网下载一个jar包，将其放置到kettle安装目录下的lib文件夹下即可。然后重启kettle即可解决
2、错误连接数据库 [222] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database
Driver class 'org.gjt.mm.mysql.Driver' could not be found, make sure the 'MySQL' driver (jar file) is installed.
org.gjt.mm.mysql.Driver
org.pentaho.di.core.exception.KettleDatabaseException:
Error occurred while trying to connect to the database
Driver class 'org.gjt.mm.mysql.Driver' could not be found, make sure the 'MySQL' driver (jar file) is installed.
org.gjt.mm.mysql.Driver
解决方案：这是因为jar包的不兼容造成，不兼容原因在文章开头已经给出，mysql-connector-java-5.1.48-bin.jar是可以解决这种兼容性问题的，所以只要到官网下载这个版本的jar包将其放置到kettle安装目录下的lib文件夹内，然后重启kettle即可解决
