# test-mbg

**Repository Path**: lucien92_lu/test-mbg

## Basic Information

- **Project Name**: test-mbg
- **Description**: 测试MyBatis动态SQL
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-09-06
- **Last Updated**: 2021-09-09

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README


### 结构

```txt
src/mian/java 
        ├── TestMbgApplication --springboot启动类
        └── com.lucine.mbg
                        ├── config --配置
                        ├── controller --控制层
                        ├── entity --实体类
                        ├── mapper --映射类
                        └── server --服务层
								└──impl --实现层

src/mian/resource
        ├── application.yml --springboot配置
        ├── generator.properties --MyBatisGenerator数据源配置
        └── generatorConfig.xml --MyBatisGenerator配置
```

### 说明

测试MyBatise的动态SQL功能

官方文档地址:https://mybatis.org/mybatis-dynamic-sql/docs/introduction.html

#### 1.完整pom文件:

```xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.5.4</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>
	<groupId>cn.lucien.mbg</groupId>
	<artifactId>test-mbg</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>test-mbg</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<!-- SpringBoot通用依赖模块 -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-aop</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<!--SpringBoot整合MyBatis -->
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>2.2.0</version>
		</dependency>
		<!--MyBatis分页插件 -->
		<dependency>
			<groupId>com.github.pagehelper</groupId>
			<artifactId>pagehelper-spring-boot-starter</artifactId>
			<version>1.3.1</version>
		</dependency>
		<!--集成druid连接池 -->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>druid-spring-boot-starter</artifactId>
			<version>1.2.6</version>
		</dependency>
		<!-- MyBatis 生成器 -->
		<dependency>
			<groupId>org.mybatis.generator</groupId>
			<artifactId>mybatis-generator-core</artifactId>
			<version>1.4.0</version>
		</dependency>
		<!-- MyBatis 动态SQL支持 -->
		<dependency>
			<groupId>org.mybatis.dynamic-sql</groupId>
			<artifactId>mybatis-dynamic-sql</artifactId>
			<version>1.2.0</version>
		</dependency>
		<!-- MySql驱动 -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<!-- Lombok -->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
				<configuration>
					<excludes>
						<exclude>
							<groupId>org.projectlombok</groupId>
							<artifactId>lombok</artifactId>
						</exclude>
					</excludes>
				</configuration>
			</plugin>
		</plugins>
	</build>

</project>

```

主要集成的依赖为:

```xml
<!--SpringBoot整合MyBatis -->
<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>2.2.0</version>
</dependency>
<!-- MyBatis 动态SQL支持 -->
<dependency>
	<groupId>org.mybatis.dynamic-sql</groupId>
	<artifactId>mybatis-dynamic-sql</artifactId>
	<version>1.2.0</version>
</dependency>
```

#### 2.整合MyBatis逆向工程

详见:

`application.yml`

`generator.properties`

`generatorConfig.xml`

`com.lucien.mbg.config.Generator.java`

#### 3.运行Generator.java生成逆向工程文件

`TMbg.java -- 测试用实体类`

`TMbgDynamicSqlSupport.java -- 实体类(TMbg)的动态SQL支持类`

`TMbgMapper.java -- 映射类`

由于  `generatorConfig.xml`中的 `<context id="MySqlContext" targetRuntime="MyBatis3DynamicSQL">`

<font color="red">**注意:** </font>***targetRuntime***配置由之前的***MyBatis3***改为***MyBatis3DynamicSQL***,将不再生成*mapper.xml文件

#### 4.创建控制层,服务层以及实现层代码,测试动态SQL功能

```java
package com.lucien.mbg.server.impl;
// 注意: 我测试的时候Eclipse需要手动import static org.mybatis.dynamic.sql.SqlBuilder.*
import static org.mybatis.dynamic.sql.SqlBuilder.isIn;

import java.util.List;

import org.mybatis.dynamic.sql.SqlBuilder;
import org.mybatis.dynamic.sql.render.RenderingStrategies;
import org.mybatis.dynamic.sql.select.render.SelectStatementProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.lucien.mbg.entity.TMbg;
import com.lucien.mbg.mapper.TMbgDynamicSqlSupport;
import com.lucien.mbg.mapper.TMbgMapper;
import com.lucien.mbg.server.ITMbgServer;

/**
 * 实现层:测试MyBatis动态SQL
 * @author Lucen_Lu
 * @date 2021/09/06
 */
@Service
public class TMbgServerImpl implements ITMbgServer {

    /** 流方式操作数据,需要java8以上 */
    private static final boolean STYLE_STREAM = true;

    @Autowired
    TMbgMapper mbgMapper;

    /* 示例:通过ID列表查询,并根据ID倒序排列*/
    @Override
    public List<TMbg> selectByIds(List<Long> ids) {
        // Eclipse自动导入crtl+shift+O不奏效
        // isIn(), 需要手动导入包,注意应为 import static:
        // import static org.mybatis.dynamic.sql.SqlBuilder.*
		// 否则isIn(ids)要写成SqlBuilder.isIn(ids)
        
        // 流方式操作数据,需要java8以上
        if (STYLE_STREAM) {
            return mbgMapper.select(s -> {
                return s.where(TMbgDynamicSqlSupport.id, isIn(ids));
            });
        }
        // 非流方式操作数据
        SelectStatementProvider selectStatement =
            // SqlBuilder
            // select id, name
            SqlBuilder.select(TMbgMapper.selectList)
                // from T_MBG
                .from(TMbgDynamicSqlSupport.TMbg)
                // where id in (ids)
                .where(TMbgDynamicSqlSupport.id, isIn(ids))
                // orderBy id desc
                .orderBy(TMbgDynamicSqlSupport.id.descending())
                //
                .build().render(RenderingStrategies.MYBATIS3);

        return mbgMapper.selectMany(selectStatement);
    }

}

```

<font color="red">**注意:** </font> Eclipse自动导入`crtl+shift+O`不奏效, `isIn()`, 需要手动`import static org.mybatis.dynamic.sql.SqlBuilder.*`,否则`isIn(ids)`要写成`SqlBuilder.isIn(ids)`.

某个大活人就是被导入包坑了很久.