【DRP】-Dao层常用功能代码：增删改查

本系列博客内容为：做DRP系统中Dao层常用功能。

该项目采用MVC架构

1. C（Controller）控制器，主要职责;1、取得表单参数；2、调用业务逻辑；3、转向页面
2. M（Model）模型，主要职责：1、业务逻辑；2、保存数据的状态
3. V（View）视图，主要职责：显示

本文主要是针对于Dao层的常见使用方法：增删改查sql语句及常用操作。

package com.bjpowernode.drp.basedata.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.bjpowernode.drp.basedata.domain.Item;
import com.bjpowernode.drp.util.ApplicationException;
import com.bjpowernode.drp.util.DbUtil;
import com.bjpowernode.drp.util.PageModel;
import com.bjpowernode.drp.util.datadict.domain.ItemCategory;
import com.bjpowernode.drp.util.datadict.domain.ItemUnit;

public class ItemDao4OracleImpl implements ItemDao {
    //增加物料信息
    public void addItem(Connection conn, Item item) {
        String sql = "insert into t_items (item_no, item_name, spec, pattern, item_category_id, item_unit_id) ";
            sql+=" values (?, ?, ?, ?, ?, ?)";
        PreparedStatement pstmt = null;
        try {
            //Dao的设计粒度一般是细粒度的，如果没有特殊需求，Dao和Manager粒度可以一样，不同考虑太多
            //Dao的设计是比较单纯的，不应该放入过多的业务逻辑（业务规则）
            //如果放置了业务逻辑，有些Manager不采用此业务逻辑，这样这个Dao方法就没有复用率了
            //对于我们的应用来说Dao最底层的，所以应该越通用越好
//            if (findItemById(conn, item.getItemNo()) != null) {
//                throw new ApplicationException("物料代码已经存在，代码=" + item.getItemNo()  + "");
//            }
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, item.getItemNo());
            pstmt.setString(2, item.getItemName());
            pstmt.setString(3, item.getSpec());
            pstmt.setString(4, item.getPattern());
            pstmt.setString(5, item.getItemCategory().getId());
            pstmt.setString(6, item.getItemUnit().getId());
            pstmt.executeUpdate();
        }catch(SQLException e) {
            e.printStackTrace();
            //System.out.println("errorCode=" + e.getErrorCode());
            //System.out.println("description=" + e.getMessage());
//            if (e.getErrorCode() == 1) {
//                throw new ApplicationException("物料代码已经存在，代码【" + item.getItemNo()  + "】");
//            }
            throw new ApplicationException("添加物料失败！");
        }finally {
            DbUtil.close(pstmt);
        }
    }
    //删除物料信息数组
    public void delItem(Connection conn, String[] itemNos) {
        StringBuffer sbString = new StringBuffer(); 
        for (int i=0; i<itemNos.length; i++) {
            sbString.append("?");
            if (i < (itemNos.length - 1)) {
                sbString.append(",");
            }
        }
        String sql = "delete from t_items where item_no in(" + sbString.toString()  + ")";
        PreparedStatement pstmt = null;
        try {
            pstmt = conn.prepareStatement(sql);
            for (int i=0; i<itemNos.length; i++) {
                pstmt.setString(i+1, itemNos[i]);
            }
            pstmt.executeUpdate();
        }catch(SQLException e) {
            e.printStackTrace();
            throw new ApplicationException("删除物料失败！");
        }finally {
            DbUtil.close(pstmt);
        }
    }
    //通过Id查询物料信息
    public Item findItemById(Connection conn, String itemNo) {
        StringBuffer sbSql = new StringBuffer();
        //第一中方法
        sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.item_category_id, ")
             .append("b.name as item_category_name, a.item_unit_id, c.name as item_unit_name ")
             .append("from t_items a, t_data_dict b, t_data_dict c ")
             .append("where a.item_category_id=b.id and a.item_unit_id=c.id and a.item_no=?");

//        //第二中方法         
//        sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.category as category_id, ")
//             .append("(select b.name from t_data_dict b where a.category=b.id) as category_name, ")
//             .append("a.unit as unit_id, ")
//             .append("(select c.name from t_data_dict c where a.unit=c.id) as unit_name ")
//             .append("from t_items a where a.item_no=?");
        
        //通常采用日志组件记录，如log4j, 级别：info,debug,error...
        
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        Item item = null;
        try {
            pstmt = conn.prepareStatement(sbSql.toString());
            pstmt.setString(1, itemNo);
            rs = pstmt.executeQuery();
            if (rs.next()) {
                item = new Item();
                item.setItemNo(rs.getString("item_no"));
                item.setItemName(rs.getString("item_name"));
                item.setSpec(rs.getString("spec"));
                item.setPattern(rs.getString("pattern"));
                //构造ItemCategory
                ItemCategory ic = new ItemCategory();
                ic.setId(rs.getString("item_category_id"));
                ic.setName(rs.getString("item_category_name"));
                item.setItemCategory(ic);
            
                
                //构造ItemUnit
                ItemUnit iu = new ItemUnit();
                iu.setId(rs.getString("item_unit_id"));
                iu.setName(rs.getString("item_unit_name"));
                item.setItemUnit(iu);
            }
        }catch(SQLException e) {
            e.printStackTrace();
            //记录到日志文件 error
            throw new ApplicationException("根据物料代码查询出错，物料代码[" + itemNo + "]");
        }finally {
            DbUtil.close(rs);
            DbUtil.close(pstmt);
        }
        return item;
    }
    //根据pageNO、pageSize、condation显示很多物料信息列表
    public PageModel findItemList(Connection conn, int pageNo, int pageSize, String condation) {
        StringBuffer sbSql = new StringBuffer();

        //第一中方法
//        sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.item_category_id, ")
//             .append("b.name as item_category_name, a.item_unit_id, c.name as item_unit_name ")
//             .append("from t_items a, t_data_dict b, t_data_dict c ")
//             .append("where a.item_category_id=b.id and a.item_unit_id=c.id and a.item_no=?");

//        //第二中方法         
//        sbSql.append("select a.item_no, a.item_name, a.spec, a.pattern, a.category as category_id, ")
//             .append("(select b.name from t_data_dict b where a.category=b.id) as category_name, ")
//             .append("a.unit as unit_id, ")
//             .append("(select c.name from t_data_dict c where a.unit=c.id) as unit_name ")
//             .append("from t_items a where a.item_no=?");
        
        sbSql.append("select * ")
            .append("from (")
                .append("select i.*, rownum rn from (")
                .append("select a.item_no, a.item_name, a.spec, a.pattern, a.item_category_id, ")
                .append("b.name as item_category_name, a.item_unit_id, c.name as item_unit_name ")
                .append("from t_items a, t_data_dict b, t_data_dict c ")
                .append("where a.item_category_id=b.id and a.item_unit_id=c.id  ");
                if (condation != null && !"".equals(condation)) {
                    sbSql.append(" and (a.item_no like '" + condation + "%' or a.item_name like '" + condation + "%') ");
                }
                sbSql.append(" order by a.item_no")
                .append(") i where rownum<=? ")
                .append(") ")
                .append("where rn >? ");
        System.out.println("sql=" + sbSql.toString());
                
        //通常采用日志组件记录，如log4j, 级别：info,debug,error...
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        PageModel pageModel = null;
        try {
            pstmt = conn.prepareStatement(sbSql.toString());
            pstmt.setInt(1, pageNo * pageSize);
            pstmt.setInt(2, (pageNo - 1) * pageSize);
            rs = pstmt.executeQuery();
            List itemList = new ArrayList();
            while (rs.next()) {
                Item item = new Item();
                item.setItemNo(rs.getString("item_no"));
                item.setItemName(rs.getString("item_name"));
                item.setSpec(rs.getString("spec"));
                item.setPattern(rs.getString("pattern"));
                //构造ItemCategory
                ItemCategory ic = new ItemCategory();
                ic.setId(rs.getString("item_category_id"));
                ic.setName(rs.getString("item_category_name"));
                item.setItemCategory(ic);
                
                //构造ItemUnit
                ItemUnit iu = new ItemUnit();
                iu.setId(rs.getString("item_unit_id"));
                iu.setName(rs.getString("item_unit_name"));
                item.setItemUnit(iu);
                
                itemList.add(item);
            }
            pageModel = new PageModel();
            pageModel.setPageNo(pageNo);
            pageModel.setPageSize(pageSize);
            pageModel.setList(itemList);
            //根据条件取得记录数
            int totalRecords = getTotalRecords(conn, condation);
            pageModel.setTotalRecords(totalRecords);
        }catch(SQLException e) {
            e.printStackTrace();
            //记录到日志文件 error
            throw new ApplicationException("分页查询失败");
        }finally {
            DbUtil.close(rs);
            DbUtil.close(pstmt);
        }
        return pageModel;
    }

    /**
     * 根据条件取得记录数
     * @param conn
     * @param queryStr
     * @return
     */
    private int getTotalRecords(Connection conn, String condation) 
    throws SQLException {
        String sql = "select count(*) from t_items ";
        if (condation != null && !"".equals(condation)) {
            sql+="where item_no like '" + condation + "%' or item_name like '" + condation + "%' ";
        }
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        int temp = 0;
        try {
            pstmt = conn.prepareStatement(sql);
            rs = pstmt.executeQuery();
            rs.next();
            temp = rs.getInt(1);
        }finally {
            DbUtil.close(rs);
            DbUtil.close(pstmt);
        }
        return temp;
    }    
    //修改物料信息
    public void modifyItem(Connection conn, Item item) {
        String sql = "update t_items set item_name=?, spec=?, pattern=?, item_category_id=?, item_unit_id=? ";
        sql+=" where item_no=?";
        PreparedStatement pstmt = null;
        try {
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, item.getItemName());
            pstmt.setString(2, item.getSpec());
            pstmt.setString(3, item.getPattern());
            pstmt.setString(4, item.getItemCategory().getId());
            pstmt.setString(5, item.getItemUnit().getId());
            pstmt.setString(6, item.getItemNo());
            pstmt.executeUpdate();
        }catch(SQLException e) {
            e.printStackTrace();
            throw new ApplicationException("修改物料失败！");
        }finally {
            DbUtil.close(pstmt);
        }
    }

    
}