MYSQL在服务端8小时不活动自动关闭。。
之后程序异常
之后程序异常
复制内容到剪贴板
程序代码
程序代码com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.io.EOFException STACKTRACE: java.io.EOFException at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1963) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2375) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2874) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1623) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1715) at com.mysql.jdbc.Connection.execSQL(Connection.java:3249) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1268) at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1403) at sun.reflect.GeneratedMethodAccessor145.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.logicalcobwebs.proxool.ProxyStatement.invoke(ProxyStatement.java:68) at org.logicalcobwebs.cglib.proxy.Proxy$ProxyImpl$$EnhancerByCGLIB$$c2f715fa.executeQuery(<generated>) at com.chinajavaworld.base.database.DbUser.loadFromDb
Tags: Exception
You can't specify target table for update in FROM clause
mysql> Update EACONTACTGROUPS A
SET GROUPNAME=(Select CONCAT(B.GROUPNAME,'-',A.GROUPNAME) FROM EACONTACTGROUPS B Where B.CORPID=A.CORPID AND B.USERID=A.USERID AND B.GROUPID=A.PARENTGROUPID)
Where A.PARENTGROUPID IS NOT NULL;
ERROR 1093 (HY000): You can't specify target table 'A' for update in FROM clause
上面是目前MYSQL5.0仍然有的限制，文档中说：
In general, you cannot modify a table and select from the same table in a subquery. For example, this limitation applies to statements of the following forms:
mysql> Update EACONTACTGROUPS A
SET GROUPNAME=(Select CONCAT(B.GROUPNAME,'-',A.GROUPNAME) FROM EACONTACTGROUPS B Where B.CORPID=A.CORPID AND B.USERID=A.USERID AND B.GROUPID=A.PARENTGROUPID)
Where A.PARENTGROUPID IS NOT NULL;
ERROR 1093 (HY000): You can't specify target table 'A' for update in FROM clause
上面是目前MYSQL5.0仍然有的限制，文档中说：
In general, you cannot modify a table and select from the same table in a subquery. For example, this limitation applies to statements of the following forms:
引用内容最近一次在用phpmyadmin导入mysql数据库时，偶的15M的数据库不能导入,mysql数据库最大只能导入2M..
phpmyadmin数据库导入出错：
You probably tried to upload too large file. Please refer to documentation for ways to workaround this limit.
可以修改导入数据库文件最大限制吗?
到网上搜索了一下前人的解决办法，大多数都说修改php.ini中的upload_max_filesize，但修改了这个以后，还是提示这个问题；但phpmyadmin在提示这个问题的时候，右下角有一行英文提示，大致意思是说，解决这个问题，可以参考phpmyadmin文档；直接点击这个链接，phpmyadmin自动查找到了以下说明：
phpmyadmin数据库导入出错：
You probably tried to upload too large file. Please refer to documentation for ways to workaround this limit.
可以修改导入数据库文件最大限制吗?
到网上搜索了一下前人的解决办法，大多数都说修改php.ini中的upload_max_filesize，但修改了这个以后，还是提示这个问题；但phpmyadmin在提示这个问题的时候，右下角有一行英文提示，大致意思是说，解决这个问题，可以参考phpmyadmin文档；直接点击这个链接，phpmyadmin自动查找到了以下说明：
