### mybatis xxx join 做连接查询
引入以下依赖
```xml
<dependency>  
    <groupId>com.github.yulichang</groupId>  
    <artifactId>mybatis-plus-join-boot-starter</artifactId>  
    <version>1.4.9</version>  
</dependency>
```

``` JAVA

import com.baomidou.mybatisplus.extension.service.IService;
to
import com.github.yulichang.base.MPJBaseService;


import com.baomidou.mybatisplus.core.mapper.BaseMapper;
to
import com.github.yulichang.base.MPJBaseMapper;

LambdaQueryWrapper
to
MPJLambdaWrapper

```

### 批量 性能 优化
> https://developer.aliyun.com/article/1055592
```
rewriteBatchedStatements=true
```