求MIN(),MAX(),COUNT(),…这几种函数时,需要根据某一个指标进行分组,需要在sql的最后加上 group by **… 异常源码: org.springframework.jdbc.BadSqlGrammarException: PreparedStatementCallback; bad SQL grammar [select region_code as nname, s
具体异常为: Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 51,440,515 milliseconds ago. The last packet sent successfully to
啥都先别想,去自己的druid;properties文件看一下配置是不是有错误 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago.