對表的增刪改查.doc

如：A表中有 a1,b1,c1,a2 四個字段，B表中有b1,b2，兩個字段，C表中有c1,c2兩個字段,a1,b1,c1分別為 A,B,C表的主鍵，現(xiàn)要對A表進行增、刪、改，sql語句寫法？本人設計時考慮時，遇到的第一個問題：a1為A的ID，a2為其名字，b1、c1為B、C的ID，b2,c2為名字，界面設計時把b1，c1字段都設計為下拉框，但現(xiàn)在我遇到的表B中字段特別多，如果都設計為下拉框，半個屏幕都成了下拉框，以及后臺操作用的sql語句也不知道怎么寫？會者幫忙，謝謝！ 對我有用0丟個板磚0引用舉報管理TOP 回復次數(shù)：11 bea_java(灰常)等級：#1樓 得分：10回復于：2009-08-09 23:41:36如果你用了hibernate就設置級聯(lián)刪除如果沒有用hibernate 就需要 寫n條sql語句了，先刪除子表，然后刪除主表內(nèi)容，不過這個要注意使用事務去處理。對我有用0丟個板磚0引用舉報管理TOP精華推薦：【投票】對于達到一定結貼率的樓主【不】在使用【機器人】提示其結貼信息?，F(xiàn)征求大家的意見 bea_java(灰常)等級：#1樓 得分：10回復于：2009-08-09 23:41:36如果你用了hibernate就設置級聯(lián)刪除如果沒有用hibernate 就需要 寫n條sql語句了，先刪除子表，然后刪除主表內(nèi)容，不過這個要注意使用事務去處理。對我有用0丟個板磚0引用舉報管理TOP精華推薦：【投票】對于達到一定結貼率的樓主【不】在使用【機器人】提示其結貼信息?，F(xiàn)征求大家的意見zl3450341(東走西顧)等級：2#2樓 得分：0回復于：2009-08-09 23:56:24beanJava codepackage org.bean;public class FligthInfo private int flightId; private String fligthNo; private String fligthTime; private String fligthPrice; private int corporationId; /B表字段 private String corporationName; /B表字段 public int getFlightId() return flightId; public void setFlightId(int flightId) this.flightId = flightId; public String getFligthNo() return fligthNo; public void setFligthNo(String fligthNo) this.fligthNo = fligthNo; public String getFligthTime() return fligthTime; public void setFligthTime(String fligthTime) this.fligthTime = fligthTime; public String getFligthPrice() return fligthPrice; public void setFligthPrice(String fligthPrice) this.fligthPrice = fligthPrice; public int getCorporationId() return corporationId; public void setCorporationId(int corporationId) this.corporationId = corporationId; public String getCorporationName() return corporationName; public void setCorporationName(String corporationName) this.corporationName = corporationName; DAOJava codepackage org.dao;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import org.bean.FligthInfo;import org.util.ConDB;public class FligthDao /查 public ArrayList findAllFligth() ArrayList fligthList =new ArrayList(); Connection con=ConDB.getConnection(); String sql=select * from T_flight a,T_corporation b where a.corporation_Id=b.corporation_Id; System.out.println(sql); Statement stm=null; ResultSet rs=null; try stm=con.createStatement(); rs=stm.executeQuery(sql); while(rs.next() FligthInfo fligth=new FligthInfo(); fligth.setCorporationId(rs.getInt(corporation_Id); fligth.setCorporationName(rs.getString(corporation_name); fligth.setFlightId(rs.getInt(flight_Id); fligth.setFligthNo(rs.getString(flight_no); fligth.setFligthPrice(rs.getString(price); fligth.setFligthTime(rs.getString(flight_time); fligthList.add(fligth); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); finally ConDB.closeRs(rs); ConDB.closeStm(stm); ConDB.closeCon(con); return fligthList; /增 public int insertFligth(FligthInfo fligth) int flag=-1; Connection con=ConDB.getConnection(); String sql=insert into T_flight values(+fligth.getFligthNo()+,+fligth.getFligthTime()+,+fligth.getFligthPrice()+,+fligth.getCorporationId()+); System.out.println(sql); Statement stm=null; try stm=con.createStatement(); flag=stm.executeUpdate(sql); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace(); finally ConDB.closeStm(stm); ConDB.closeCon(con); return flag; servlet 添加數(shù)據(jù)Java codepackage org.service;import java.io.IOException;import java.io.PrintWriter;import java.util.ArrayList;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.bean.FligthInfo;import org.dao.FligthDao;public class InsertFligth extends HttpServlet /* * The doGet method of the servlet. * * This method is called when a form has its tag value method equals to get. * * param request the request send by the client to the server * param response the response send by the server to the client * throws ServletException if an error occurred * throws IOException if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException FligthInfo fligth=new FligthInfo(); fligth.setFligthNo(request.getParameter(fligthNo); fligth.setFligthPrice(request.getParameter(fligthPrice); fligth.setCorporationId(Integer.parseInt(request.getParameter(corporationId); fligth.setFligthTime(request.getParameter(fligthTime); FligthDao fDao=new FligthDao(); fDao.insertFligth(fligth); request.getRequestDispatcher(/servlet/FindAllFligth).forward(request, response); /* * The doPost method of the servlet. * * This method is called when a form has its tag value method equals to post. * * param request the request send by the client to the server * param response the response send by the server