SpringBoot 刨坑记（二）generator自动生成mybatis实体类时多出了WithBLOBs和Key类

最新推荐文章于 2024-04-20 18:36:56 发布

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最新推荐文章于 2024-04-20 18:36:56 发布

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分类专栏： springboot 文章标签： springboot mysql8.0 connector8.x/J mybatis generator

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在尝试解决问题的时候，也找了很多的博客，很多说法是数据库表的字段类型使用了text，因为在不查询大字段时，用Example就足够了，update同理，而检索大字段时，必须使用WithBLOBs。还有则说是字段中用了二进制。
可是上述情况都不是我的碰见的，但还是生成了***WithBLOBs.java文件。以下就我的问题和解决方法:

[WARNING] Some problems were encountered while building the effective model for com:demo:jar:0.0.1-SNAPSHOT
[WARNING] 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique: mysql:mysql-connector-java:jar -> version (?) vs 8.0.11 @ line 84, column 15
[WARNING] 'dependencies.dependency.scope' for org.springframework.boot:spring-boot-devtools:jar must be one of [provided, compile, runtime, test, system] but is 'true'. @ line 94, column 11
[WARNING] 
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING] 
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING] 
……
[INFO] Introspecting table user
[INFO] Generating Example class for table user
[INFO] Generating Primary Key class for table user
[INFO] Generating Record class for table user
[INFO] Generating Record class (with BLOBs) for table user
[INFO] Generating Mapper Interface for table user
[INFO] Generating SQL Map for table user
[INFO] Generating Example class for table user
[INFO] Generating Record class for table user
[INFO] Generating Mapper Interface for table user
[INFO] Generating SQL Map for table user
[INFO] Saving file UserMapper.xml
[INFO] Saving file UserMapper.xml
[INFO] Saving file UserExample.java
[INFO] Saving file UserKey.java
[INFO] Saving file User.java
[INFO] Saving file UserWithBLOBs.java
[INFO] Saving file UserMapper.java
[INFO] Saving file UserExample.java
[INFO] Saving file User.java
[INFO] Saving file UserMapper.java
[WARNING] Table Configuration user matched more than one table (mysql..user,houserent..user)
[WARNING] Column id, specified as an identity column in table user, does not exist in the table.

在这里插入图片描述

原因
?使用了version 8.x 的 Connector/J

因为我的 Mysql 版本是8.0，所以使用的Connector也是8.0，很多博客说要把Connector用回低版本，这样就不会出现问题，但是官方文档是建议使用8.x

在[MyBatis Generator] 的官方英文文档中有提到这个问题：→MyBatis Generator

If you are using version 8.x of Connector/J you may notice that the generator attempts to generate code for tables in the MySql information schemas (sys, information_schema, performance_schema, etc.) This is probably not what you want! To disable this behavior, add the property “nullCatalogMeansCurrent=true” to your JDBC URL.
For example:

<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost/my_schema"
            userId="my_user" password="my_password">
        <property name="nullCatalogMeansCurrent" value="true" />
</jdbcConnection>

翻译过来就是：

如果您使用的是Connector / J的8.x版，您可能会注意到生成器尝试为MySql信息模式（sys，information_schema，performance_schema等）中的表生成代码。这可能不是您想要的！要禁用此行为，请将属性“nullCatalogMeansCurrent = true”添加到JDBC URL。

将该属性加入进config.xml文件中，重新生成代码，可以看见之前的 UserWithBLOBs.java 和 UserKey.java 文件不再生成了。
在这里插入图片描述

以下是几个警告的解决：

1.重复引用了依赖包，在pom文件中删除多余的依赖

[WARNING] 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique: mysql:mysql-connector-java:jar -> version (?) vs 8.0.11 @ line 84, column 15

2.依赖包中的参数问题

[WARNING] 'dependencies.dependency.scope' for org.springframework.boot:spring-boot-devtools:jar must be one of [provided, compile, runtime, test, system] but is 'true'. @ line 89, column 11

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-devtools</artifactId>
	<optional>true</optional>
	<scope>test</scope> <!--此处的设置-->
</dependency>