?? core_operation.java
字號:
try{
PreparedStatement preSQLSelect=dbconn.prepareStatement(sqlString);
preSQLSelect.setInt(1,lession_id);
preSQLSelect.setLong(2,student_id);
rs=preSQLSelect.executeQuery();
if(rs.next()) return 3;//已存在此學生成績記錄
//--------更新記錄-----------
sqlString="update core set lession_id=?,student_id=? where core_id=?";
PreparedStatement preSQLUpdate=dbconn.prepareStatement(sqlString);
preSQLUpdate.setInt(1,lession_id);
preSQLUpdate.setLong(2,student_id);
preSQLUpdate.setLong(3,core_id);
preSQLUpdate.executeUpdate();
return 1;
}catch(Exception e){
System.out.print(e);
return 2;
}
}
/**
* 功能:根據學生ID及課程ID得到學生成績
* 輸入參數:student_id學生ID號,lession_id為課程ID號
* 輸出參數:成績字符串,查找不到或出錯返回“”
*/
public String getStudent_lession_core(long student_id,int lession_id){
String sqlString=null;//SQL語句字符串
Statement sql=null;//SQL語句對象
dbconn dbconnOBject=new dbconn();//數據庫連接對象
ResultSet rs=null;//結果記錄集
Connection dbconn=dbconnOBject.getDBConn();//得到數據庫連接
if(dbconn==null) return "";//連接失敗
if(student_id==0||lession_id==0) return "";//輸入參數不正確
sqlString="select core from core where lession_id="+lession_id+" and" +
" student_id="+student_id;
try{
sql=dbconn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=sql.executeQuery(sqlString);
if(rs.next()) return(rs.getString("core"));
else return "";
}catch(Exception e){
System.out.print(e);
return "";
}
}
/**
* 功能:批量保存學生成績
* 輸入：refName為要修改的學生ID號數組，refValue為學生ID號數組數組對應的成績值，
* lession_id為要修改成績的課程ID號
* 輸出：修改成功與否的信息提示字符串
*/
public String saveStudent_core(String refName[],String refValue[],int lession_id){
String returnString=new String("");
String sqlString=null;//SQL語句字符串
Statement sql=null;//SQL語句對象
ResultSet rs=null;//結果記錄集
dbconn dbconnOBject=new dbconn();//數據庫連接對象
Connection dbconn=dbconnOBject.getDBConn();//得到數據庫連接
if(dbconn==null) return returnString;//連接失敗
if(refName.length==0||refValue.length==0||lession_id==0)//沒有學生成績數據
return returnString;
PreparedStatement preSQLUpdate=null;//更新SQL語句對象
for(int i=0;i<refName.length;i++){
if(refName[i]!=null&&refValue[i]!=null)
try{
float core=Float.parseFloat(refValue[i]);
if(core>=0&&core<=100){//輸入成績數據合法
sqlString="select * from core where lession_id=" +
""+lession_id+" and student_id="+refName[i];
sql=dbconn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=sql.executeQuery(sqlString);
if(rs.next()){
sqlString="update core set core=? where lession_id=" +
""+lession_id+" and student_id="+refName[i];
sqlString=sqlString+" and close_status=0";
preSQLUpdate=dbconn.prepareStatement(sqlString);
preSQLUpdate.setFloat(1,Float.parseFloat(refValue[i]));
int updateCount=preSQLUpdate.executeUpdate();
if(updateCount==1)
returnString=returnString+"更新序號為"+refName[i]+"的課程成績成功!<br>";
else
returnString=returnString+"更新序號為"+refName[i]+"的課程成績失敗!原因:狀態不正常!<br>";
}else{
sqlString="insert into core(lession_id,student_id,core) values(" +
""+lession_id+","+refName[i]+","+refValue[i]+")";
preSQLUpdate=dbconn.prepareStatement(sqlString);
preSQLUpdate.executeUpdate();
returnString=returnString+"插入序號為"+refName[i]+"的課程成績成功!<br>";
}
System.out.println(sqlString);
}
else{
returnString=returnString+"插入或更新序號為"+refName[i]+"的課程成績失敗,原因:輸入數據非法!<br>";
}
}catch(Exception e){
System.out.println(e);
System.out.println(sqlString);
returnString=returnString+"更新序號為"+refName[i]+"的課程成績失敗!<br>";
}
}
return returnString;
}
/**
* 功能：學生用學生成績查詢功能
* 輸入：class_id為學生所在班級ID號，student_name為學生名字
* 輸出：此學生的成績記錄集
* 說明：只能查詢出一個學生的成績
*/
public ResultSet student_core_view(int class_id,String student_name){
String sqlString=null;//SQL語句字符串
Statement sql=null;//SQL語句對象
ResultSet rs=null;//結果記錄集
dbconn dbconnOBject=new dbconn();//數據庫連接對象
if(student_name==null||student_name.length()==0)
return null;
Connection dbconn=dbconnOBject.getDBConn();//得到數據庫連接
if(dbconn==null) return null;//連接失敗
try{
//-------查詢出數據------------
sqlString="select student.student_name as student_name," +
"lession.lession_name as lession_name,core.core as core" +
" from student,core,lession,class" +
" where core.student_id=student.student_id and" +
" core.lession_id=lession.lession_id";
if(class_id!=0)
sqlString=sqlString+" and class.class_id="+class_id+" and " +
"student.class_id="+class_id;
if(student_name!=null&&student_name.trim().length()!=0)
sqlString=sqlString+" and student.student_name='" +
""+student_name+"'";
sql=dbconn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
//System.out.println(sqlString);
rs=sql.executeQuery(sqlString);
return rs;
}catch(Exception e){
e.printStackTrace();
return null;
}
}
/**
* 功能：得到班級某功課的所有成績
* @param class_id
* @param lession_id
* @return
*/
public ResultSet getClassLessionCore(int class_id,int lession_id){
String sqlString=null;//SQL語句字符串
Statement sql=null;//SQL語句對象
ResultSet rs=null;//結果記錄集
dbconn dbconnOBject=new dbconn();//數據庫連接對象
Connection dbconn=dbconnOBject.getDBConn();//得到數據庫連接
if(dbconn==null) return null;//連接失敗
sqlString="select * from core";
if(class_id==0||lession_id==0){
if(!(lession_id==0&&class_id==0)){
if(class_id==0)
sqlString=sqlString+" where lession_id="+lession_id;
if(lession_id==0)
sqlString="select core.core as core from core,student " +
" where student.student_id=core.student_id" +
" and student.class_id="+class_id;
}
}else{
sqlString="select core.core as core from core,student " +
" where student.student_id=core.student_id" +
" and student.class_id="+class_id +"" +
" and core.lession_id="+lession_id;
}
try{
sql=dbconn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
rs=sql.executeQuery(sqlString);
return rs;
}catch(Exception e){
System.out.print(e);
return null;
}
}
}
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