异常报错：

 ERROR --- [ionPool-Create-1772825962] com.alibaba.druid.pool.DruidDataSource   : create connection SQLException, url: jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true, errorCode 0, state 08001
==>
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server.
        at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:67)
        at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:484)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
        at com.mysql.jdbc.Util.getInstance(Util.java:372)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:958)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:937)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:872)
        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2316)
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2069)
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
        at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:67)
        at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:484)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
        at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1657)
        at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1723)
        at com.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidDataSource.java:2801)
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Map.get(Object)" because "this.serverVariables" is null
        at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:2989)
        at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1873)
        at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1802)
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1206)
        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2239)
        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2270)
        ... 12 common frames omitted
<==

解决：

1、引入MySQL版本对应的jar包，Seata默认提供了两个版本的，如果没有可自行引入

2、修改数据库的连接配置

store.db.driverClassName=com.mysql.cj.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true&serverTimezone=GMT%2B8

seata官方提供的连接默认没有serverTimezone，MySQL8必须得指定一个值，如果是注册到Nacos，可直接修改Nacos中的这两个值即可，改完后重启Seata