I am using the following code to access sql server database table record. I can confirm that the table columns are retrieved. But due to some reasons, it does not retrieve any row. Am I missing anything?
I am using remote server MS SQL Server.
try {
try {
Class.forName("net.sourceforge.jtds.jdbc.Driver").newInstance();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
try {
Connection DbConn = DriverManager.getConnection("jdbc:jtds:sqlserver://ServerName/DBName;user=sa;password=password");
Statement stmt = DbConn.createStatement();
ResultSet reset = stmt.executeQuery("select * from tblUser");
String str = reset.getString(1);
DbConn.close();
} catch (SQLException e) {
}
} catch (Exception e) {
e.printStackTrace();
}
You need to call ResultSet#next() to advance the cursor to the first record of the result set. From the Javadoc:
Moves the cursor froward one row from its current position. A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes the second row the current row, and so on.
So your code should look like this:
try {
String cs = "jdbc:jtds:sqlserver://ServerName/DBName;user=sa;password=password";
Connection DbConn = DriverManager.getConnection(cs);
Statement stmt = DbConn.createStatement();
ResultSet reset = stmt.executeQuery("select * from tblUser");
while (reset.next()) {
String str = reset.getString(1);
// do something with this record
}
DbConn.close();
} catch (SQLException e) {
// handle exception here
}
The initial pointer is located before the first row, so if you want the first result like in your example, do:
if(reset.next()) {
String s = r.getString(1);
}
I'm trying to add data from a csv file to an sqlite database on Android.
My data in csv file looks like this
SID,Attended,Serial,Time,Title,Forenames,Last name,Parking,How many people will be in your party (including yourself)?,Any access requirements?,Access requirements,Timetable
9290,,0000000092906,2014-04-07 18:44:59,Miss,foo1,foo1,,2,No,,fooo
9291,,0000000092907,2014-04-08 18:44:59,Miss,foo2,foo2,,2,No,,fooo
9292,,0000000092908,2014-04-07 18:44:59,Miss,foo3,foo3,,2,No,,fooo
I created a DatabaseHelper to import it :
public void importFromCSV(String filename)
{
//deleteTable();
SQLiteDatabase db = this.getReadableDatabase();
String next[] = {};
try {
db.beginTransaction();
CSVReader reader = new CSVReader(new FileReader(filename));
reader.readNext();
for(;;) {
next = reader.readNext();
if(next != null) {
this.addPerson(new Person(Long.parseLong(next[0]),
next[1],
Long.parseLong(next[2]),
next[3],
next[4],
next[5],
next[6],
next[7],
Integer.parseInt(next[8]),
next[9],
next[10],
next[11]));
} else {
break;
}
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
finally {
db.endTransaction();
}
}
But when I try to do a SELECT on my database, I got an error : CursorIndexOutOfBoundsException : Index 0 requested, with a size of 0.
I did some research and found that this error was because of an empty cursor.
Here is my getPerson function :
public Person getPerson(long sid){
// 1. get reference to readable DB
SQLiteDatabase db = this.getReadableDatabase();
// 2. build query
Cursor cursor =
db.query(TABLE_PERSONS, // a. table
COLUMNS, // b. column names
" sid = ?", // c. selections
new String[] { String.valueOf(sid) }, // d. selections args
null, // e. group by
null, // f. having
null, // g. order by
null); // h. limit
// 3. if we got results get the first one
if (cursor != null) {
cursor.moveToFirst();
}
// 4. build pers object
Person pers = new Person();
pers.setSid(Long.parseLong(cursor.getString(0)));
pers.setAttended(cursor.getString(1));
pers.setSerial(Long.parseLong(cursor.getString(2)));
pers.setTime(cursor.getString(3));
pers.setTitle(cursor.getString(4));
pers.setForename(cursor.getString(5));
pers.setLastname(cursor.getString(6));
pers.setParking(cursor.getString(7));
pers.setNumberpeople(Integer.parseInt(cursor.getString(8)));
pers.setAccessreqornot(cursor.getString(9));
pers.setAccessreq(cursor.getString(10));
pers.setTimetable(cursor.getString(11));
Log.d("getPerson()", pers.toString());
// 5. return pers
return pers;
}
I think the issue is due to my addPerson function called in importFromCsv().
My log at the beginning of the addPerson function returns me the right thing, but I think the db.insert is not going well. But I don't have any error on this.
My addPerson function :
public void addPerson(Person pers){
Log.d("addPerson", pers.toString());
// 1. get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// 2. create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put(SID, pers.getSid());
values.put(ATTENDED, pers.getAttended());
values.put(SERIAL, pers.getSerial());
values.put(TIME, pers.getTime());
values.put(TITLE, pers.getTitle());
values.put(FORENAME, pers.getForename());
values.put(LASTNAME, pers.getLastname());
values.put(PARKING, pers.getParking());
values.put(NUMBERPEOPLE, pers.getNumberpeople());
values.put(ACCESSREQORNOT, pers.getAccessreqornot());
values.put(ACCESSREQ, pers.getAccessreq());
values.put(TIMETABLE, pers.getTimetable());
// 3. insert
db.insert(TABLE_PERSONS, // table
null, //nullColumnHack
values); // key/value -> keys = column names/ values = column values
}
Thanks for your reading time, I would be really grateful if someone had any idea.
EDIT : Stacktrace :
07-08 12:01:57.755: D/addPerson(10828): Person [sid=9290, attended=, serial=92906, time=2014-04-07 18:44:59, title=Miss, forename=Ladina, lastname=Clement, parking=, numberpeople=2, accessreqornot=No, accessreq=, timetable=Fine]
07-08 12:01:57.755: D/addPerson(10828): Person [sid=9291, attended=, serial=92907, time=2014-04-08 18:44:59, title=Miss, forename=Ladina2, lastname=Clement2, parking=, numberpeople=2, accessreqornot=No, accessreq=, timetable=Fine]
07-08 12:01:57.763: D/addPerson(10828): Person [sid=9292, attended=, serial=92908, time=2014-04-07 18:44:59, title=Miss, forename=Ladina3, lastname=Clement3, parking=, numberpeople=2, accessreqornot=No, accessreq=, timetable=Fine]
07-08 12:01:59.193: D/ViewRootImpl(10828): ViewRoot TouchDown(Absolute) DOWN (357 , 189)
07-08 12:01:59.247: D/getAllPersons()(10828): []
Change this line:
if (cursor != null) {
cursor.moveToFirst();
}
to
if (!cursor.moveToFirst()) {
// do something when there are no results
}
The null check on the cursor is redundant. You can check if the cursor is empty by doing cursor.moveToFirst(). If it returns false you should prevent executing further commands on the cursor like you are doing later e.g. cursor.getString(0).
My data is like this:
25-07-14 12:00,15,52,16,50,42,58,63,62,52
22-06-14 14:00,15,52,16,50,42,58,63,62,52
12-09-14 19:00,45,51,16,50,42,58,13,34,52
02-02-14 16:00,15,52,16,50,42,58,63,62,52
01-05-14 12:00,15,52,16,50,42,58,63,62,52
i have read that data like this you can find once. In the file path i am checking is that csv file are not.
FilePath = data.getData().getPath();
if(FilePath.substring(FilePath.length()-4).endsWith(".csv"))
And the code is here
private void readcsvfile() {
if(FilePath.length()>4)
{
dataGridTable = new DgaDataGridTable(context);
equipmentTable = new EquipmentTable(context);
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(FilePath)));
String line;
while ((line=reader.readLine())!=null)
{
info = new DgaDataGridInfo();
String[] rowData = line.split(",");
if(rowData[0].length()!=0&&rowData[1].length()!=0&&rowData[2].length()!=0&&rowData[3].length()!=0&&rowData[4].length()!=0&&rowData[5].length()!=0&&rowData[6].length()!=0&&rowData[7].length()!=0&&rowData[8].length()!=0&&rowData[9].length()!=0)
{
info.setDateadded(rowData[0]);
info.setH2(Integer.parseInt(rowData[1]));
info.setCh4(Integer.parseInt(rowData[2]));
info.setC2h2(Integer.parseInt(rowData[3]));
info.setC2h4(Integer.parseInt(rowData[4]));
info.setC2h6(Integer.parseInt(rowData[5]));
info.setCo(Integer.parseInt(rowData[6]));
info.setCo2(Integer.parseInt(rowData[7]));
info.setO2(Integer.parseInt(rowData[8]));
info.setN2(Integer.parseInt(rowData[9]));
info.setTdcg(Integer.parseInt(rowData[1])+Integer.parseInt(rowData[2])+Integer.parseInt(rowData[5])+Integer.parseInt(rowData[4])+Integer.parseInt(rowData[3])+Integer.parseInt(rowData[6]));
equipmentname = equipment_spinner.getSelectedItem().toString();
info.setEquipid(equipmentTable.getEquipmentId(equipmentname));
dataGridTable.insertRecord(info);
Toast.makeText(this, "Dga Records Succesfully Added", Toast.LENGTH_LONG).show();
loadAllDgaRecords();
}
else
{
showAlertDialog();
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
else
Toast.makeText(this, "Please choose csv file", Toast.LENGTH_LONG).show();
}
Thanks
I have ORMLite database with some fields. I want to select titles from the table where id == id which I get from webservice. I do like that:
try {
Dao<ProcessStatus,Integer> dao = db.getStatusDao();
Log.i("status",dao.queryForAll().toString());
QueryBuilder<ProcessStatus,Integer> query = dao.queryBuilder();
Where where = query.where();
String a = null;
for(Order r:LoginActivity.orders) {
//LoginActivity.orders - array of my objects which I get from webservice
Log.i("database",query.selectRaw("select title from process_status").
where().rawComparison(ProcessStatus.STATUS_ID, "=",
r.getProcess_status().getProccessStatusId()).toString());
}
Log.i("sr",a);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
I tried like this but I get only sets of my id, not titles. I tried like this:
Log.i("database", query.selectColumns(ProcessStatus.STATUS_TITLE).where().
eq(ProcessStatus.STATUS_ID, r.getProcess_status().getProccessStatusId())
.toString());
but I have the same result. How should I get data from database?
For selecting an specific field from the table, you could do something like this:
String result = "";
try {
GenericRawResults<String[]> rawResults = yourDAO.queryRaw("select " +
ProcessStatus.STATUS_TITLE +" from YourTable where "+
ProcessStatus.STATUS_ID + " = " +
r.getProcess_status().getProccessStatusId());
List<String[]> results = rawResults.getResults();
// This will select the first result (the first and maybe only row returned)
String[] resultArray = results.get(0);
//This will select the first field in the result which should be the ID
result = resultArray[0];
} catch (Exception e) {
e.printStackTrace();
}
Hope this helps.
It's hard to properly answer this question without seeing all of the classes of the processStatusId field and others. However I think you are doing too much raw method and may not be properly escaping your values and the like.
I would recommend that you use the IN SQL statement instead of what you are doing in the loop. Something like:
List<String> ids = new ArrayList<String>();
for(Order r : LoginActivity.orders) {
ids.add(r.getProcess_status().getProccessStatusId());
}
QueryBuilder<ProcessStatus, Integer> qb = dao.queryBuilder();
Where where = qb.where();
where.in(ProcessStatus.STATUS_ID, ids);
qb.selectColumns(ProcessStatus.STATUS_TITLE);
Now that you have built your query, either you can retrieve your ProcessStatus objects or you can get the titles themselves using dao.queryForRaw(...):
List<ProcessStatus> results = qb.query();
// or use the prepareStatementString method to get raw results
GenericRawResults<String[]> results = dao.queryRaw(qb.prepareStatementString());
// each raw result would have a String[] with 1 element for the title
i am looking to make game of questions and answers.i had taken a textview and 4 radio group buttons.and i am fetching data from the external data file from the assets folder.when i installs the app into the emulater it works fine.when i reopens the app in the emulater it is just showing question not showing any text in the radio buttons.here is my code in the data base file
public String makeatext(String My_database_table,int i) {
SQLiteDatabase myDB = getDatabase();
String results = new String();
try {
String firstColumn = "questions";
// final String KEY_ROWID = "id";
// Cursor c = myDB.rawQuery("SELECT questions FROM " +
// My_database_table+ ";",null);
Cursor c = myDB.query(true, My_database_table,
new String[] { firstColumn },null, null, null, null, null,
null);
int iquestion = c.getColumnIndex(firstColumn);
if(c.moveToPosition(i)){
results = c.getString(iquestion)+"\n";
}
//while (c.moveToPosition(1)) {
//String firstName = c.getString(iquestion);
//results =(" "+ firstName + " ");
//}
return results;
} catch (Exception e) {
Log.e("ERROR","ERROR in Make test file :"+e.toString());
e.printStackTrace();
// TODO: handle exception
}
return results;
}
and in the Activity file i am just calling it as
String shoow = myDb.makeatext("question", Qno);
showQuestion.setText(shoow);
and on the top of the oncreate methode i initilized the data base asprivate final DataBaseHelper myDb = new DataBaseHelper(this);
can any one say me why this is happenig.do i need to write the for loop in the activity file also or shall i take a cursor in the activity class .
plz help me out
thanks in advance
for radio buttons the code in the database file is as follows as i have 4 buttons the code for 4 buttons will be as same as this
public String makeExtra1(String My_database_table ,int positions) {
String results = new String();
try {
String secondColumn = "Extra1";
Cursor c = myDataBase.query(true, My_database_table,
new String[] { secondColumn }, null, null, null, null, null,
null);
int iExtra1 = c.getColumnIndex(secondColumn);
if(c.moveToPosition(positions)){
results = results+c.getString(iExtra1)+"\n";
}
return results;
} catch (Exception e) {
Log.e("ERROR","ERROR in Make test file :"+e.toString());
e.printStackTrace();
// TODO: handle exception
}
return results;}
and in the Activity file
String showextra1 = myDb.makeExtra1("question", Qno);
r0.setText(showextra1);
i repeted this thing for 4 times as changing the makeExtra2,3,4 and in the assinged to r1,r2,r3 as above.
You should call Cursor.close() after reading data from it. Better to do it finally{} block.
If you want to raise only one answer per query - fill where param of myDataBase.query().
The unreachable code error is because you are writing finally{} block after return results;
Move this line after the finally{} block, eclipse will not give you any error.
Also do use myDB.close(); in this finally block.