老师，我的后台报错。应该是mybatis和数据库之间的错误，麻烦您看下

org.apache.ibatis.exceptions.PersistenceException:

### Error querying database. Cause: java.sql.SQLSyntaxErrorException: Table 'message_board.users' doesn't exist

### The error may exist in mapper/userMappers.xml

### The error may involve defaultParameterMap

### The error occurred while setting parameters

### SQL: select * from users

### Cause: java.sql.SQLSyntaxErrorException: Table 'message_board.users' doesn't exist

at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:150)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)

at com.damu.dao.UsersDao.findAll(UsersDao.java:14)

at com.damu.servlet.UsersServlet.doPost(UsersServlet.java:21)

at com.damu.servlet.UsersServlet.doGet(UsersServlet.java:28)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)

at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)

at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800)

at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)

at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806)

at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)

at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

at java.lang.Thread.run(Thread.java:748)

Caused by: java.sql.SQLSyntaxErrorException: Table 'message_board.users' doesn't exist

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:118)

at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:95)

at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)

at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:960)

at com.mysql.cj.jdbc.ClientPreparedStatement.execute(ClientPreparedStatement.java:388)

at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63)

at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)

at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)

at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)

at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)

at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)

at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83)

at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)

... 29 more

进入servlet了

org.apache.ibatis.exceptions.PersistenceException:

### Error querying database. Cause: org.apache.ibatis.executor.ExecutorException: Executor was closed.

### Cause: org.apache.ibatis.executor.ExecutorException: Executor was closed.