錯誤場景：
- 使用 mybatis-plus 的 getById()方法，返回結果竟然是多條記錄。
- 參數已確定是主鍵id。
- 通過數據庫可視化工具 執行sql 返回是一條記錄。
通過可視化工具執行sql是一條記錄，但是 通過 mybatis-plus 的getById() 方法確是多條記錄。
錯誤日志：
org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.TooManyResultsException: Expected one result (or null) to be returned by selectOne(), but found: 2
at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:92)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:440)
at com.sun.proxy.$Proxy153.selectOne(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:159)
at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.execute(MybatisMapperMethod.java:90)
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy$PlainMethodInvoker.invoke(MybatisMapperProxy.java:148)
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:89)
at com.sun.proxy.$Proxy156.selectById(Unknown Source)
at com.baomidou.mybatisplus.extension.service.IService.getById(IService.java:199)
at com.baomidou.mybatisplus.extension.service.IService$$FastClassBySpringCGLIB$$f8525d18.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:685)
at cn.com.chnsys.eleac4.sys_common.service.impl.ConfigRuleDetailServiceImpl$$EnhancerBySpringCGLIB$$4e131247.getById(<generated>)
at cn.com.chnsys.eleac4.rule.RuleApplicationTests.test3(RuleApplicationTests.java:91)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:675)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:125)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:132)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:124)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:74)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:104)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:62)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:43)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:35)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:202)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:198)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at java.util.ArrayList.forEach(ArrayList.java:1249)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at java.util.ArrayList.forEach(ArrayList.java:1249)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)
Caused by: org.apache.ibatis.exceptions.TooManyResultsException: Expected one result (or null) to be returned by selectOne(), but found: 2
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:80)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
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)
... 75 more
sql查詢日志：
Creating a new SqlSession
SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@140fa482] was not registered for synchronization because synchronization is not active
JDBC Connection [HikariProxyConnection@2027818863 wrapping com.mysql.jdbc.JDBC4Connection@3b063aaf] will not be managed by Spring
==> Preparing: SELECT ID,ZONGTPZID AS configTotalId,ZONGTPZLX AS configTotalType,ZONGTPZMC AS configTotalName,XUNCXMC AS configRuleDetailName,ZHUCID AS registrId,JISGZ AS calRule,BEIYZFC8 AS ReservedString8,BEIYZFC7 AS ReservedString7,BEIYZFC6 AS ReservedString6,BEIYZFC5 AS ReservedString5,BEIYZFC4 AS ReservedString4,BEIYZFC3 AS ReservedString3,BEIYZFC2 AS ReservedString2,BEIYZFC1 AS ReservedString1,BEIYZT5 AS ReservedInt5,BEIYZT4 AS ReservedInt4,BEIYZT3 AS ReservedInt3,BEIYZT2 AS ReservedInt2,BEIYZT1 AS ReservedInt1 FROM eleac_guizpz WHERE ID=?
==> Parameters: 4(Integer)
<== Columns: ID, configTotalId, configTotalType, configTotalName, configRuleDetailName, registrId, calRule, ReservedString8, ReservedString7, ReservedString6, ReservedString5, ReservedString4, ReservedString3, ReservedString2, ReservedString1, ReservedInt5, ReservedInt4, ReservedInt3, ReservedInt2, ReservedInt1
<== Row: 4, 4, 4, 完整性, 完整性, 2, <<BLOB>>, null, null, null, null, null, null, null, null, null, null, null, null, null
<== Row: 4C56B386-8257-4991-A6BF-29D2EEFBF299, 1, 1, 及時性, 行政二審外部卷宗規則, 1, <<BLOB>>, null, null, null, null, null, null, null, null, null, null, null, null, null
<== Total: 2
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@140fa482]
錯誤分析
實體對象主鍵 id 數據類型是 String，數據庫主鍵類型為 varcher。但是程序傳遞給 mybatis-plus的getById()方法 的參數類型卻是Integer
在sql查詢日志中可以看到：==> Parameters: 4(Integer)
sql的參數為Integer，與實體數據類型不同。與mybayis-plus底層原理有關，此處不進行分析。
錯誤解決：修改查詢參數為string，
Creating a new SqlSession
SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@439047ef] was not registered for synchronization because synchronization is not active
JDBC Connection [HikariProxyConnection@2114163679 wrapping com.mysql.jdbc.JDBC4Connection@301b2259] will not be managed by Spring
==> Preparing: SELECT ID,ZONGTPZID AS configTotalId,ZONGTPZLX AS configTotalType,ZONGTPZMC AS configTotalName,XUNCXMC AS configRuleDetailName,ZHUCID AS registrId,JISGZ AS calRule,BEIYZFC8 AS ReservedString8,BEIYZFC7 AS ReservedString7,BEIYZFC6 AS ReservedString6,BEIYZFC5 AS ReservedString5,BEIYZFC4 AS ReservedString4,BEIYZFC3 AS ReservedString3,BEIYZFC2 AS ReservedString2,BEIYZFC1 AS ReservedString1,BEIYZT5 AS ReservedInt5,BEIYZT4 AS ReservedInt4,BEIYZT3 AS ReservedInt3,BEIYZT2 AS ReservedInt2,BEIYZT1 AS ReservedInt1 FROM eleac_guizpz WHERE ID=?
==> Parameters: 4(String)
<== Columns: ID, configTotalId, configTotalType, configTotalName, configRuleDetailName, registrId, calRule, ReservedString8, ReservedString7, ReservedString6, ReservedString5, ReservedString4, ReservedString3, ReservedString2, ReservedString1, ReservedInt5, ReservedInt4, ReservedInt3, ReservedInt2, ReservedInt1
<== Row: 4, 4, 4, 完整性, 完整性, 2, <<BLOB>>, null, null, null, null, null, null, null, null, null, null, null, null, null
<== Total: 1
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@439047ef]