Error:

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 query log:

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, Full, 2, <<BLOB>>, null, null, null, null, null, null, null, null, null, null, null, null, null
<==        Row: 4C56B386-8257-4991-A6BF-29D2EEFBF299, 1, 1, 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]

error analysis

Viewing the entity object, it is found that the primary key ID data type is string and the database primary key type is varcher

The parameter of SQL is integer, which is different from the entity data type. It is related to the underlying principle of mybayis plus and will not be analyzed here.

Error resolution: modify the query parameter to 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, Full, 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]