20 评论0and1

连不上

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

赞 0 2021-07-01 15:31

您好，您若是付费用户，可以联系帆软技术支持获得帮助；
若是免费用户，可以到社区进行提问：https://bbs.fanruan.com/wenda

赞 0 2021-07-06 11:17

8.0.22 无法连接成功啊!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

赞 0 2021-04-25 20:10

您可以看一下文档第 3 节

赞 0 2021-07-06 11:17

赞 0 2021-04-23 10:47

MySQL 8.0.20，本地连接测试成功，但远程连接提示如下：java.sql.SQLException: Unknown system variable 'query_cache_size'
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:963)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3966)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3902)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2526)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2673)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2503)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1369)
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3833)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3283)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2297)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.GeneratedConstructorAccessor184.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
at com.fr.third.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1461)
at com.fr.third.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1525)
at com.fr.third.alibaba.druid.pool.DruidDataSource$CreateConnectionThread.run(DruidData

赞 0 2021-04-07 17:44

可以尝试使用服务器直接连接-https://help.fanruan.com/finereport/doc-view-2560.html

赞 0 2021-04-09 11:01

既然写到了插件里，为啥不能一起做到服务器外置数据库也能用呀，做一半鸡肋了，食之无味，弃之可惜

赞 0 2021-04-01 16:28

您好，一般在没发直接连接MySQL的情况下使用插件。优先直接连接性能更好~https://help.fanruan.com/finereport/doc-view-2560.html

赞 0 2021-04-09 10:13