1. 程式人生 > >JSP實現HTML網頁對Mysql資料庫的資料修改

JSP實現HTML網頁對Mysql資料庫的資料修改

<% request.setCharacterEncoding("utf-8"); String msg=""; String msg1=""; boolean error=false; 獲取網址中傳遞的Id String origId = request.getParameter("pid"); String value1 = null; String value2 = null; String value3 = null; try{ String connectString = "jdbc:mysql://localhost/test" + "?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8"
; String user = "root"; String pwd = "mysql"; String sql = "select *from stu where id = '" + origId + "';"; Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection(connectString, user, pwd); Statement state = conn.createStatement(); 將原始Id中的資料寫入到當前的HTML中 ResultSet rs = state.executeQuery(sql); while
(rs.next()){ 注意rs是空指標,要使用rs.next才能訪問到數值 value1 = rs.getString("id"); value2 = rs.getString("name"); value3 = rs.getString("age"); } rs.close(); state.close(); conn.close(); }catch (Exception e){ e.printStackTrace(); } String s1 = request.getParameter("sub"
); if(s1!=null){ String Id = ""; String Name = ""; String Age = ""; String Grade = ""; String Hobby[]= {""}; String Hobbies = ""; for(int j = 0 ; j < 1 ; j++){ Id = ""; Name = ""; Age = ""; Grade = ""; Hobbies = ""; if(request.getParameter("Id")!=null){ Id = request.getParameter("Id"); if(Id == ""){ error = true; msg = "ID cant be empty!"; break; } if(!Id.equals(origId)){ error = true; msg = "ID cant be changed!"; break; } } if(request.getParameter("Name")!=null){ Name = request.getParameter("Name"); if(Name == ""){ error = true; msg = "Name cant be empty!"; break; } } if(request.getParameter("Age")!=null){ Age = request.getParameter("Age"); if(Age == ""){ error = true; msg = "Age cant be empty!"; break; } } if(request.getParameter("Grade")!=null){ Grade = request.getParameter("Grade"); if(Grade == ""){ error = true; msg = "Grade cant be empty!"; break; } } if(request.getParameter("Hobby")!=null){ Hobby = request.getParameterValues("Hobby"); int len = Hobby.length; for(int i = 0 ; i < len ; i++){ if(i==0){ if(len==1){ Hobbies = Hobby[0]; }else{ Hobbies = Hobbies + Hobby[i] + "+"; } }else if(i == (len-1)){ Hobbies = Hobbies + Hobby[i]; }else{ Hobbies = Hobbies + Hobby[i] + "+"; } } } if(Hobbies == ""){ error = true; msg = "Hobby cant be empty!"; break; } } 對資料庫進行修改 if(!error){ try{ String connectString = "jdbc:mysql://localhost/test" + "?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8"; String user = "root"; String pwd = "mysql"; String sql = null; Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection(connectString, user, pwd); Statement state = conn.createStatement(); sql = "update stu set name = '" + Name + "', age = '" + Age + "', grade = '" + Grade + "', hobby = '" + Hobbies +"';"; if(Hobbies==""){ msg1 = "yes"; }else{ msg1 = "no"; } int cnt = state.executeUpdate(sql); if(cnt > 0){ msg = "Update success!"; }else{ msg = "Add Error!"; } state.close(); conn.close(); }catch (Exception e){ e.printStackTrace(); } } if(msg == "Update success!"){ value1 = Id; value2 = Name; value3 = Age; } } %>