文章目录
- [1. Mybatis](#1. Mybatis)
-
- [2. Mybatis Plus](#2. Mybatis Plus)
-
- [2.1. 代码实现](#2.1. 代码实现)
- [2.2. 特别注意](#2.2. 特别注意)
- [3. PageHelper](#3. PageHelper)
-
- [3.1. 代码实现](#3.1. 代码实现)
- [3.2. 特别注意](#3.2. 特别注意)
- 参考资料
1. Mybatis
1.1. 代码实现
java
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package com.example.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan(value = "com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
java
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package com.example.demo.mapper;
import com.example.demo.model.SysUser;
import com.example.demo.model.page.BasePageReq;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
@Mapper
public interface UserMapper {
List<SysUser> page(@Param(value = "pageReq") BasePageReq pageReq);
}
xml
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
<select id="page" resultType="com.example.demo.model.SysUser">
<bind name="startIndex" value="(pageReq.pageNum-1)*pageReq.pageSize"/>
SELECT
ID AS id,
NAME AS name,
AGE AS age
FROM SYS_USER
ORDER BY ID ASC
LIMIT #{startIndex}, #{pageReq.pageSize}
</select>
</mapper>
yml
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mybatis:
mapper-locations: classpath:mapper/*.xml
type-aliases-package: com.example.demo.model
xml
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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.3.0</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.15</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>30.1-jre</version>
</dependency>
2. Mybatis Plus
2.1. 代码实现
java
复制代码
package com.example.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan(value = "com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
java
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import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
Page<SysUser> list = userMapper.page(new Page<>(pageReq.getPageNum(), pageReq.getPageSize()));
java
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package com.example.demo.mapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.demo.model.SysUser;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
@Mapper
public interface UserMapper {
Page<SysUser> page(@Param(value = "pageReq") IPage<SysUser> pageReq);
}
java
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
<select id="page" resultType="com.example.demo.model.SysUser">
SELECT ID AS id, NAME AS name, AGE AS age
FROM SYS_USER
ORDER BY ID ASC
</select>
</mapper>
yml
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mybatis-plus:
mapper-locations: classpath*:mapper/*.xml
type-aliases-package: com.example.demo.model
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
xml
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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.15</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>30.1-jre</version>
</dependency>
2.2. 特别注意
Mybatis Plus
分页功能中使用了 CCJSqlParser
,其中 CCJSqlParser#Statement
在处理 复杂 SQL
时,存在 性能问题
3. PageHelper
3.1. 代码实现
java
复制代码
package com.example.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan(value = "com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
java
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import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
Page<SysUser> list = PageHelper.startPage(pageReq.getPageNum(), pageReq.getPageSize()).doSelectPage(() -> userMapper.page());
java
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package com.example.demo.mapper;
import com.example.demo.model.SysUser;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import java.util.List;
@Mapper
public interface UserMapper {
List<SysUser> page();
}
xml
复制代码
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
<select id="page" resultType="com.example.demo.model.SysUser">
SELECT ID AS id, NAME AS name, AGE AS age
FROM SYS_USER
ORDER BY ID ASC
</select>
</mapper>
yml
复制代码
mybatis-plus:
mapper-locations: classpath*:mapper/*.xml
type-aliases-package: com.example.demo.model
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
xml
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<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.15</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>30.1-jre</version>
</dependency>
3.2. 特别注意
PageHelper
分页功能中使用了 CCJSqlParser
,其中 CCJSqlParser#Statement
在处理 复杂 SQL
时,存在 性能问题
参考资料