[Data] SpringBoot integrates MyBatis-Plus to realize paged query

build query data

-- 创建岗位信息表
CREATE TABLE `sys_post` (
  `post_id` bigint NOT NULL AUTO_INCREMENT COMMENT '岗位ID',
  `post_code` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '岗位编码',
  `post_name` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '岗位名称',
  `post_sort` int NOT NULL COMMENT '岗位排序',
  `del_flag` char(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL DEFAULT '0' COMMENT '是否删除  -1：已删除  0：正常',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  `create_by` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT '' COMMENT '创建人',
  `update_time` datetime DEFAULT NULL COMMENT '更新时间',
  `update_by` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT '' COMMENT '更新人',
  `remark` varchar(500) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT '备注信息',
  PRIMARY KEY (`post_id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin ROW_FORMAT=DYNAMIC COMMENT='岗位信息表';
 
-- 向员工表插入数据
INSERT INTO `sys_post` VALUES (1, 'user', '员工', 2, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (2, 'cto', 'cto', 0, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '秃头大佬');
INSERT INTO `sys_post` VALUES (3, 'user', '董事长', -1, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '资本家');
INSERT INTO `sys_post` VALUES (4, 'user1', '员工1', 3, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (5, 'user2', '员工2', 4, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (6, 'user3', '员工3', 5, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (7, 'user4', '员工4', 6, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (8, 'user5', '员工5', 7, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (9, 'user6', '员工6', 8, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (10, 'user7', '员工7', 9, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');
INSERT INTO `sys_post` VALUES (11, 'user8', '员工8', 10, '0', '2023-03-16 13:14:20', 'admin', '2023-06-26 13:14:20', 'admin', '打工人');

Mybatis-Plus Page

This class inherits IPagethe class and implements it. 简单分页模型If you want to implement your own paging model, you can inherit Pagethe class or implement IPagethe class

attribute name	type	Defaults	describe
records	List	emptyList	query data list
total	Long	0	Query the total number of records in the list
size	Long	10	The number of items displayed per page, the default10
current	Long	1	current page
orders	List	emptyList	Sorting field information, when allowing the front-end to pass in, pay attention to SQL injection problems, you can use to SqlInjectionUtils.check(...)check the text
optimizeCountSql	boolean	true	Automatically optimize the COUNT SQL If it jSqlParsercannot be parsed, set this parameter tofalse
optimizeJoinOfCountSql	boolean	true	Whether to automatically optimize the COUNT SQL to remove the join query part
searchCount	boolean	true	Whether to perform count query, if it points to the query list, do not query the total number of records, set this parameter tofalse
maxLimit	Long		Single page pagination limit
countId	String		xmlcustom countquerystatementId

Based on Wrapper pagination query

Demo address: mingyue-springboot-mybatis-plus

1. Add post entity

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import io.swagger.v3.oas.annotations.media.Schema;
import lombok.Data;
import lombok.EqualsAndHashCode;

/**
 * 岗位管理
 *
 * @author Strive
 * @date 2022-03-15 17:18:40
 */
@Data
@TableName("sys_post")
@EqualsAndHashCode(callSuper = true)
@Schema(description = "岗位信息表")
public class MingYuePost extends BaseEntity {

	private static final long serialVersionUID = -8744622014102311894L;

	/**
	 * 岗位ID
	 */
	@TableId(type = IdType.ASSIGN_ID)
	@Schema(description = "岗位ID")
	private Long postId;

	/**
	 * 岗位编码
	 */
	@Schema(description = "岗位编码")
	private String postCode;

	/**
	 * 岗位名称
	 */
	@Schema(description = "岗位名称")
	private String postName;

	/**
	 * 岗位排序
	 */
	@Schema(description = "岗位排序")
	private Integer postSort;

	/**
	 * 是否删除 -1：已删除 0：正常
	 */
	@Schema(description = "是否删除  -1：已删除  0：正常")
	private String delFlag;

	/**
	 * 备注信息
	 */
	@Schema(description = "备注信息")
	private String remark;

}

2. Add job Mapper

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.csp.mingyue.mybatisPlus.model.MingYuePost;
import org.apache.ibatis.annotations.Mapper;

/**
 * @author Strive
 */
@Mapper
public interface MingYuePostMapper extends BaseMapper<MingYuePost> {
}

3. Add post Service

import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.csp.mingyue.mybatisPlus.mapper.MingYuePostMapper;
import com.csp.mingyue.mybatisPlus.model.MingYuePost;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

/**
 * @author Strive
 * @date 2023/5/12 10:22
 */
@Slf4j
@Service
@RequiredArgsConstructor
public class MingYuePostService extends ServiceImpl<MingYuePostMapper, MingYuePost> {
}

4. Provide paging query interface

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.csp.mingyue.mybatisPlus.model.MingYuePost;
import com.csp.mingyue.mybatisPlus.service.MingYuePostService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.RequiredArgsConstructor;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author Strive
 * @date 2023/5/12 10:21
 */
@Api(tags = "岗位模块")
@RestController
@RequiredArgsConstructor
@RequestMapping("/post")
public class MingYuePostController {

    private final MingYuePostService mingYuePostService;

    @ApiOperation("根据用户ID查询用户信息")
    @GetMapping("/page")
    public ResponseEntity<IPage<MingYuePost>> page(Page<MingYuePost> page) {
        return ResponseEntity.ok(mingYuePostService.page(page));
    }

}

5. Add pagination interceptor

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @author Strive
 * @date 2023/5/12 15:51
 */
@Configuration
public class MyBatisPlusConfig {
    /**
     * 分页插件
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

6. Test interface

http://127.0.0.1:8080/post/page?size=5&current=1&orders%5B0%5D.column=post_sort&orders%5B0%5D.asc=true

Execute the SQL as follows:

SELECT post_id, post_code, post_name, post_sort, del_flag, remark, create_by, create_time, update_by, update_time FROM sys_post ORDER BY post_sort ASC LIMIT 5

The returned data is as follows:

{
    "records": [
        {
            "createBy": "admin",
            "createTime": "2023-03-16T13:14:20",
            "updateBy": "admin",
            "updateTime": "2023-06-26T13:14:20",
            "postId": 3,
            "postCode": "boss",
            "postName": "董事长",
            "postSort": -1,
            "delFlag": "0",
            "remark": "资本家"
        },
        {
            "createBy": "admin",
            "createTime": "2023-03-16T13:14:20",
            "updateBy": "admin",
            "updateTime": "2023-06-26T13:14:20",
            "postId": 2,
            "postCode": "cto",
            "postName": "cto",
            "postSort": 0,
            "delFlag": "0",
            "remark": "秃头大佬"
        },
        {
            "createBy": "admin",
            "createTime": "2023-03-16T13:14:20",
            "updateBy": "admin",
            "updateTime": "2023-06-26T13:14:20",
            "postId": 1,
            "postCode": "user",
            "postName": "员工",
            "postSort": 2,
            "delFlag": "0",
            "remark": "打工人"
        },
        ...
    ],
    "total": 11,
    "size": 5,
    "current": 1,
    "orders": [
        {
            "column": "post_sort",
            "asc": true
        }
    ],
    "optimizeCountSql": true,
    "searchCount": true,
    "countId": null,
    "maxLimit": null,
    "pages": 3
}

SQL-based pagination query

1. Add pagination query Mapper

/**
  * 分页查询岗位信息
  * @param page 分页参数
  * @param mingYuePost
  * @return
  */
IPage<MingYuePost> selectPageSql(@Param("page") Page page,@Param("query") MingYuePost mingYuePost);

2. Write Mapper.xml

<?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.csp.mingyue.mybatisPlus.mapper.MingYuePostMapper">
    <resultMap id="mingYuePostMap" type="com.csp.mingyue.mybatisPlus.model.MingYuePost">
        <id property="postId" column="post_id"/>
        <result property="postCode" column="post_code"/>
        <result property="postName" column="post_name"/>
        <result property="postSort" column="postSort"/>
        <result property="delFlag" column="del_flag"/>
        <result property="createTime" column="create_time"/>
        <result property="createBy" column="create_by"/>
        <result property="updateTime" column="update_time"/>
        <result property="updateBy" column="update_by"/>
        <result property="remark" column="remark"/>
    </resultMap>

    <select id="selectPageSql" resultMap="mingYuePostMap">
        SELECT p.post_id,
               p.post_name,
               p.post_code,
               p.post_sort as postSort,
               p.del_flag,
               p.create_time,
               p.update_time,
               p.update_by,
               p.create_by,
               p.remark
        FROM sys_post p
        <where>
            p.del_flag = '0'
            <if test="query.postName != null and query.postName != ''">
                <bind name="postNameLike" value="'%' + query.postName + '%'" />
                and p.post_name LIKE  #{postNameLike}
            </if>
        </where>
        <if test="null != page.orders">
            <include refid="dynamicOrder"></include>
        </if>
    </select>

    <!-- 动态排序 -->
    <sql id="dynamicOrder">
        ORDER BY
        <choose>
            <when test="page.orders != null and page.orders.size > 0">
                <foreach collection="page.orders" item="order" separator=",">
                    ${order.column}
                    <choose>
                        <when test="order.asc == true">
                            asc
                        </when>
                        <otherwise>
                            desc
                        </otherwise>
                    </choose>
                </foreach>
            </when>
        </choose>
    </sql>
</mapper>

3. Write Service

public IPage<MingYuePost> pageSql(Page page, MingYuePost mingYuePost) {
        return mingYuePostMapper.selectPageSql(page, mingYuePost);
}

4. Write the interface

@ApiOperation("分页查询岗位信息(SQl)")
@GetMapping("/pageSql")
public ResponseEntity<IPage<MingYuePost>> pageSql(Page page, MingYuePost mingYuePost) {
  return ResponseEntity.ok(mingYuePostService.pageSql(page, mingYuePost));
}

5. Test interface

http://127.0.0.1:8080/post/pageSql?postName=%E5%91%98%E5%B7%A5&orders%5B0%5D.column=postSort&orders%5B0%5D.asc=false&size=5&current=1

Execute the SQL as follows:

SELECT p.post_id, p.post_name, p.post_code, p.post_sort AS postSort, p.del_flag, p.create_time, p.update_time, p.update_by, p.create_by, p.remark FROM sys_post p WHERE p.del_flag = '0' AND p.post_name LIKE '%员工%' ORDER BY postSort DESC, postSort DESC LIMIT 5

The returned data is as follows:

{
    "records": [
        {
            "createBy": "admin",
            "createTime": "2023-03-16T13:14:20",
            "updateBy": "admin",
            "updateTime": "2023-06-26T13:14:20",
            "postId": 11,
            "postCode": "user8",
            "postName": "员工8",
            "postSort": 10,
            "delFlag": "0",
            "remark": "打工人"
        },
        {
            "createBy": "admin",
            "createTime": "2023-03-16T13:14:20",
            "updateBy": "admin",
            "updateTime": "2023-06-26T13:14:20",
            "postId": 10,
            "postCode": "user7",
            "postName": "员工7",
            "postSort": 9,
            "delFlag": "0",
            "remark": "打工人"
        },
        {
            "createBy": "admin",
            "createTime": "2023-03-16T13:14:20",
            "updateBy": "admin",
            "updateTime": "2023-06-26T13:14:20",
            "postId": 9,
            "postCode": "user6",
            "postName": "员工6",
            "postSort": 8,
            "delFlag": "0",
            "remark": "打工人"
        },
      	...
    ],
    "total": 0,
    "size": 10,
    "current": 1,
    "orders": [
        {
            "column": "postSort",
            "asc": false
        }
    ],
    "optimizeCountSql": true,
    "searchCount": true,
    "countId": null,
    "maxLimit": null,
    "pages": 0
}