一、异常

在这里插入图片描述

### Error querying database.  Cause: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
### The error may exist in file [D:\JetBrains\Idea\workspace\zohe\bjxz\ruoyi-system\target\classes\mapper\business\device\AlertInfoMapper.xml]
### The error may involve com.zhuohe.business.mapper.AlertInfoMapper.selectAlertInfoList_COUNT
### The error occurred while handling results
### SQL: SELECT count(0) FROM alert_info a LEFT JOIN scene b ON a.scene_id = b.scene_id WHERE a.alert_type = ?
### Cause: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
	at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:30)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:149)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140)
	at sun.reflect.GeneratedMethodAccessor89.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:426)
	... 124 common frames omitted
Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
	at java.util.ArrayList.rangeCheck(ArrayList.java:653)
	at java.util.ArrayList.get(ArrayList.java:429)
	at org.apache.shardingsphere.core.merge.dql.DQLMergeEngine.<init>(DQLMergeEngine.java:71)
	at org.apache.shardingsphere.core.merge.MergeEngineFactory.newInstance(MergeEngineFactory.java:58)
	at org.apache.shardingsphere.shardingjdbc.jdbc.core.statement.ShardingPreparedStatement.getResultSet(ShardingPreparedStatement.java:139)
	at sun.reflect.GeneratedMethodAccessor96.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:69)
	at com.sun.proxy.$Proxy147.getResultSet(Unknown Source)
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getFirstResultSet(DefaultResultSetHandler.java:237)
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:187)
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:65)
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
	at sun.reflect.GeneratedMethodAccessor94.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:63)
	at com.sun.proxy.$Proxy145.query(Unknown Source)
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:325)
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
	at com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor.intercept(MybatisPlusInterceptor.java:65)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
	at com.sun.proxy.$Proxy144.query(Unknown Source)
	at sun.reflect.GeneratedMethodAccessor193.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:63)
	at com.sun.proxy.$Proxy144.query(Unknown Source)
	at com.github.pagehelper.util.ExecutorUtil.executeAutoCount(ExecutorUtil.java:166)
	at com.github.pagehelper.PageInterceptor.count(PageInterceptor.java:157)
	at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:100)
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
	at com.sun.proxy.$Proxy144.query(Unknown Source)
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:147)
	... 129 common frames omitted

二、原因

一开始我还以为Mybatis的问题也是糊涂啊，没仔细看报错代码，找了半天，各种debug 最后看到走到了shardingsphere 的源码中报错了。最后还发现是分表查询的时候会有一个组合的过程，然后比如我发生的问题 alert_info 表与 alert_info2022(无数据) 结果集组合的过程发生了异常。

使用shardingsphere 4.0.0-RC1 版本

 <dependency>
     <groupId>org.apache.shardingsphere</groupId>
     <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
     <version>4.0.0-RC1</version>
 </dependency>
 <dependency>
      <groupId>org.apache.shardingsphere</groupId>
      <artifactId>sharding-jdbc-spring-namespace</artifactId>
      <version>4.0.0-RC1</version>
  </dependency>

三、解决方法

换个 shardingsphere 版本
这里我将 4.0.0-RC1 换成了 4.1.1

<dependency>
            <groupId>org.apache.shardingsphere</groupId>
            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
            <version>4.1.1</version>
</dependency>

4.1.1 版本与 4.0.0-RC1 有些差异需要注意

druid 需要单独引入不能使用 druid-spring-boot-starter 会报错 DataSource注入失败的问题

  <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.6</version>
        </dependency>