【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);
         }
     }

 }