java编码实现根据某个字段分组，再统计某个值

最新推荐文章于 2024-07-03 15:29:34 发布

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本文介绍了如何使用Java结合MyBatis框架，根据数据库中的某个字段进行数据分组，并对分组后的数据进行统计操作，具体实现包括数据库实体类和输出实体类的设计与使用。

实现层逻辑如下：

@Override
    public DesignChangeChangedAmountVo queryChangedAmounts() {
        List<DesignChange> designChangeList = this.lambdaQuery()
                .eq(DesignChange::getStatus, Constants.DesignChangeStatus.SHEN_PI_TONG_GUO)
                .eq(DesignChange::getDelFlag, CommonConstant.DEL_FLAG_0)
                .list();

        DesignChangeChangedAmountVo result = new DesignChangeChangedAmountVo();
        //根据合同分组
        Map<String, List<DesignChange>> contractMap = designChangeList.stream()
                .collect(Collectors.groupingBy(DesignChange::getContractId));

        List<DesignChangeChangedAmountVo.ContractTotalChangedAmounts> contracts = new ArrayList<>();
        contractMap.keySet().forEach(i -> {
            List<DesignChange> ls = contractMap.get(i);
            DesignChangeChangedAmountVo.ContractTotalChangedAmounts info = new DesignChangeChangedAmountVo.ContractTotalChangedAmounts();
            info.setContractId(ls.get(0).getContractId());
            info.setContractName(ls.get(0).getContractName());
            //累计造价咨询单位审核金额
            BigDecimal totalChangedAmount = ls.stream().map(DesignChange::getCostConsultUnitAuditAmount)
                    .filter(Objects::nonNull)
                    .reduce(BigDecimal.ZERO, BigDecimal::add);
            info.setContractTotalChangedAmount(totalChangedAmount);
            contracts.add(info);
        });
        //根据工程分组
        Map<String, List<DesignChange>> projectMap = designChangeList.stream()
                .collect(Collectors.groupingBy(DesignChange::getProjectCode));
        List<DesignChangeChangedAmountVo.ProjectTotalChangedAmount> projects = new ArrayList<>();
        projectMap.keySet().forEach(i -> {
            List<DesignChange> ls = projectMap.get(i);
            DesignChangeChangedAmountVo.ProjectTotalChangedAmount info = new DesignChangeChangedAmountVo.ProjectTotalChangedAmount();
            info.setProjectCode(ls.get(0).getProjectCode());
            info.setProjectName(ls.get(0).getProjectName());
            //累计造价咨询单位审核金额
            BigDecimal totalChangedAmount = ls.stream().map(DesignChange::getCostConsultUnitAuditAmount)
                    .filter(Objects::nonNull)
                    .reduce(BigDecimal.ZERO, BigDecimal::add);
            info.setProjectTotalChangedAmount(totalChangedAmount);
            projects.add(info);
        });

        result.setContractAmounts(contracts);
        result.setProjectAmounts(projects);

        return result;
    }

数据库实体类：

package com.bytz.modules.sw.pm.constr.design.entity;

import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableLogic;
import com.baomidou.mybatisplus.annotation.TableName;
import com.bytz.common.aspect.annotation.Dict;
import com.bytz.common.entity.IFlowEntity;
import com.bytz.modules.sw.common.model.ISwEntity;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Date;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.EqualsAndHashCode;

@Data
@EqualsAndHashCode(callSuper = false)
@TableName("pm_constr_design_change")
@ApiModel(value = "DesignChange对象", description = "工程建设项目管理—施工管理—设计变更表")
public class DesignChange implements Serializable, ISwEntity, IFlowEntity {

    private static final long serialVersionUID = 1L;

    @TableId("ID")
    private String id;

    @ApiModelProperty(value = "工程编号")
    @TableField("PROJECT_CODE")
    private String projectCode;

    @ApiModelProperty(value = "工程名称")
    @TableField("PROJECT_NAME")
    private String projectName;

    @ApiModelProperty(value = "合同ID")
    @TableField("CONTRACT_ID")
    private String contractId;

    @ApiModelProperty(value = "合同名称")
    @TableField("CONTRACT_NAME")
    private String contractName;

    @ApiModelProperty(value = "造价咨询单位审核金额 (正式)")
    @TableField("COST_CONSULT_UNIT_AUDIT_AMOUNT")
    private BigDecimal costConsultUnitAuditAmount;

    @ApiModelProperty(value = "造价咨询单位意见")
    @TableField("COST_CONSULT_UNIT_OPINION")
    private String costConsultUnitOpinion;

    @ApiModelProperty(value = "变更最终审定金额 (正式)")
    @TableField("CHANGED_FINAL_AUDIT_AMOUNT")
    private BigDecimal changedFinalAuditAmount;

    @ApiModelProperty(value = "创建人")
    @TableField("CREATE_BY")
    private String createBy;

    @ApiModelProperty(value = "创建人姓名")
    @TableField("CREATE_BY_NAME")
    private String createByName;

    @ApiModelProperty(value = "创建时间")
    @TableField("CREATE_TIME")
    private Date createTime;

    @ApiModelProperty(value = "更新人")
    @TableField("UPDATE_BY")
    private String updateBy;

    @ApiModelProperty(value = "更新人姓名")
    @TableField("UPDATE_BY_NAME")
    private String updateByName;

    @ApiModelProperty(value = "更新时间")
    @TableField("UPDATE_TIME")
    private Date updateTime;

    @ApiModelProperty(value = "删除标识")
    @TableField("DEL_FLAG")
    @TableLogic
    private Integer delFlag;

    @ApiModelProperty(value = "状态")
    @TableField("STATUS")
    @Dict(dicCode = "pm_constr_design_change_status")
    private String status;
}

输出实体类：

package com.bytz.modules.sw.pm.constr.design.model;

import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.EqualsAndHashCode;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.List;

@Data
@EqualsAndHashCode(callSuper = false)
public class DesignChangeChangedAmountVo implements Serializable {

    private static final long serialVersionUID = 1L;

    @ApiModelProperty("合同累计变更金额集合")
    List<ContractTotalChangedAmounts> contractAmounts;

    @ApiModelProperty("工程累计变更金额集合")
    List<ProjectTotalChangedAmount> projectAmounts;

    @Data
    public static class ContractTotalChangedAmounts{

        @ApiModelProperty(value = "合同ID")
        private String contractId;

        @ApiModelProperty(value = "合同名称")
        private String contractName;

        @ApiModelProperty(value = "合同累计已变更金额 (正式)")
        private BigDecimal contractTotalChangedAmount;
    }

    @Data
    public static class ProjectTotalChangedAmount{

        @ApiModelProperty(value = "工程编号")
        private String projectCode;

        @ApiModelProperty(value = "工程名称")
        private String projectName;

        @ApiModelProperty(value = "工程累计已变更金额 (正式)")
        private BigDecimal projectTotalChangedAmount;
    }
}