2021-08-03

程序包org.junit不存在

junit
junit
test

java.lang.Exception: Method groupList should have no parameters
@Test 声明单元测试是要求void修饰方法且方法无参

Type interface com.copote.comb.hub.mapper.GroupMapper is not known to the MybatisPlusMapperRegistry.

MybatisSqlSessionFactoryBean - Property ‘mapperLocations’ was not specified.
mybatis-plus.mapper-locations:classpath*:/org.apache.dolphinscheduler.dao.mapper/*.xml

com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

Job for mysqld.service failed because the control process exited with error code

vi /var/log/mysqld.log

键盘上数字“1”左侧（ESC下方）的按键是“~”和英文“·”的按键。
“~”英文符号叫“ Tilde” ,(意思是 颚化符号,鼻音化符号,代字号）。中文俗称“波浪号”。
“·”叫做“间隔号”，用于某些非汉语人名内部或书目中。比如外国人和某些少数民族人名内各部分的分界，用间隔号标示。书名与篇（章、卷）名之间的分界，用间隔号标示。

Mapper组建

1、Mapper文件和Mapper接口应该放在同一个接口中
2、Mapper文件中的namespace应该设置为Mapper接口的全限定名称
3、Mapper文件中的操作元素ID对应Mapper接口的方法名称
4、接口名必须与Mybatis的映射文件名一定要一模一样，如果不一样就会报如下错

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): org.xx.demo.mapper.xx.xx

究其原因是mybatis-config.xml的配置文件的原因

1.在注册映射文件时使用标签时，需要映射文件名和接口名一样，不然会报错。

2.在注册映射文件时使用mapper标签的class属性时，需要映射文件名和接口名一样，不然会报错。

3.在注册映射文件时使用，不需要映射文件名和接口名一样

CURD语句的基本使用 对表中数据的操作一般分为四类, 常记做 “CURD”: C: 创建(Create) U: 更新(Update) R: 读取(Retrieve) D: 删除(Delete) 1.INSERT 插入 完整…

Exception in thread “main” org.apache.ibatis.exceptions.PersistenceException:

Error building SqlSession.

The error may exist in mybatis/mapper/TestMapper.xml

The error occurred while processing mapper_resultMap[BaseResultMap]

Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is ‘mybatis/mapper/TestMapper.xml’. Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.ipark.dao.TestMapper.BaseResultMap

Error updating database. Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for com.ipark.dao.TestMapper.insertSelective

Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for com.ipark.dao.TestMapper.insertSelective

20210805==========================================================================================
Exception:org.springframework.jdbc.BadSqlGrammarException:

Error updating database. Cause: java.sql.SQLSyntaxErrorException: Unknown column ‘group_name’ in ‘field list’

The error may exist in com/copote/comb/hub/mapper/GroupMapper.java (best guess)

Cause: java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘1’ for key ‘t_hub_group.PRIMARY’

; Duplicate entry ‘1’ for key ‘t_hub_group.PRIMARY’; nested exception is java.sql.SQLIntegrityConstraintViolationException: Duplicate entry ‘1’ for key ‘t_hub_group.PRIMARY’

An error occurred while collecting items to be installed
session context was:(profile=epp.package.jee, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
Unable to read repository at https://checkstyle.org/eclipse-cs-update-site/releases/8.43.0.202106150125/plugins/net.sf.eclipsecs.checkstyle_8.43.0.202106150125.jar.
Read timed out
Unable to read repository at https://checkstyle.org/eclipse-cs-update-site/releases/8.43.0.202106150125/plugins/net.sf.eclipsecs.core_8.43.0.202106150125.jar.
Premature end of Content-Length delimited message body (expected: 12262726; received: 2110575