I created a database with a table named flagTable, this table only has two fields, which are id(auto increment) and an integer field. Next, in my program, I have a button that will trigger a thread to start. When the thread is starting, it constantly retrieve data from database, and check for the for the value, if the value is equal to one then it will trigger another new Thread, something like this:
private class statusOfStrummingInAnotherDevice extends Thread {
int value;
public void run() {
try{
while(true){
try{
if(flagCursor == null){
flagCursor = cdb1.getFlagAll();
}
}catch(Exception e){break;}
try{
Log.i("MAIN3ACTIVITY","getting status");
int size = cdb1.getSize(flagCursor);
Log.i("MAIN3ACTIVITY","SIZE is" + String.valueOf(xyz));
for(int i = 0 ; i < size ; i++){
flagCursor.moveToPosition(i);
Log.i("MAIN3ACTIVITY","getting status jkasdfasdf");
value = cdb1.getFlag();
if(value == 1){
Log.i("FLAGCURSOR=====>>>>","Succesful");
releasingNotes = new ReleasingNotes(IntendedChord);
releasingNotes.start();
//break;
}
cdb1.updateFlag(0);
Log.i("FLAGCURSOR=====>>>>",String.valueOf(value));
}
flagCursor = null;
}catch(Exception e){break;}
Log.i("MAIN3ACTIVITY","thread is sleeping");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
break;
}
}
}catch(Exception e){
}
}
}
In the meantime, the data that were retrieved from the database is using this function:
public Cursor getFlagAll(){
return getReadableDatabase().rawQuery(
"SELECT _ID, flag from flagTable", null);
}
And, the data that were updated to the database through this method:
public int updateFlag(int i) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put("flag",i);
return db.update("flagTable" , contentValues , "_ID" + "= ?",new String[]{String.valueOf(1)});
}
Now, above codes will give no error, however, the data that were retrieved from the database is always 1, it keeps trigger a new function. In my above codes, I stated if the value is equal to 1, then the current thread will trigger a new thread to start, When its finished, the program will update the current data to 0. So that, the next round of the infinite loop can stop triggering new thread until a the conditon is met. What is problem overhere? did my codes really updated the new value? or I need to referesh the database every time I updated a new value.
Use Listeners to your database.
use SQLiteTransactionListener and do your things in onCommit()
Some guide in details here :
https://developer.android.com/reference/android/database/sqlite/SQLiteTransactionListener.html and
http://www.programcreek.com/java-api-examples/index.php?api=android.database.sqlite.SQLiteTransactionListener
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
Here My update database table methods
public void insertionchallanval(ArrayList<String> itemcode,ArrayList<String> item,ArrayList<String> quantity,
ArrayList<String> date,ArrayList<String> status,ArrayList<String> id)
{
ContentValues insertValues = new ContentValues();
for(int i=0;i<status.size();i++)
{
if(!retriveidstatus(id.get(i)))
{
insertValues.put("id", id.get(i));
insertValues.put("itemcode", itemcode.get(i));
insertValues.put("item", item.get(i));
insertValues.put("status", status.get(i));
insertValues.put("date", date.get(i));
insertValues.put("quantity", quantity.get(i));
//insertValues.put("category", category.get(i));
myDataBase.insert("create_challan", null, insertValues);
}
else
{
insertValues.put("id", id.get(i));
insertValues.put("itemcode", itemcode.get(i));
insertValues.put("item", item.get(i));
insertValues.put("quantity", quantity.get(i));
insertValues.put("status", status.get(i));
insertValues.put("date", date.get(i));
//insertValues.put("category", category.get(i));
myDataBase.update("create_challan", insertValues, "id="+"'"+id.get(i)+"'",null );
}
}
}
Here my check Id Methods
public boolean retriveidstatus(String id)
{
Cursor curCalllog = myDataBase.rawQuery("SELECT id FROM create_challan", null);
if(curCalllog.moveToNext() && curCalllog != null) {
while(!curCalllog.isAfterLast())
{
if(id.contains(curCalllog.getString(0)))
{
return true;
}
curCalllog.moveToNext();
}
}
return false;
}
Table Structure
id String
status String
date String
challanno String
itemcode String
item String
quantity String
When i call methods for insertion new value then its working fine but when i call again with new updated value then update methods return 0 means no row effected
Please Help me how i can fix this problem
Thanks IN Advance
Instead of checking wether the _IDs exist or not you can use replace() method of the class SQLiteDatabase like this :
myDataBase.replace("create_challan", null, insertValues);
hope it helps Cheers :)
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.
I have created complied statement given below. Now my question is how to get resultset of the query.
Here is my code:
DataBaseHelper dbHelper=new DataBaseHelper(context);
dbHelper.createDataBase();
dbHelper.openDataBase();
SQLiteDatabase db = dbHelper.getWritableDatabase();
SQLiteStatement st=db.compileStatement("select taskid from task where taskdate=?");
st.bindString(1,"2011/09/05");
st.execute();
This works without any error. But I want the result set of the given query. Please help..
The result set isn't available, at least for now, in sqlite. It all depends on exactly what information you want from the ResultSet or ResultSetMetaData, etc, but there are other means of obtaining almost the same information.
You can get detailed information about the columns in a table with the following, used as if it were a SELECT, and the information about the columns will be presented:
pragma table_info(myTable) ;
See http://www.sqlite.org/pragma.html#pragma_table_info for more information.
If you want the information concerning a specific SELECT, you can get information from the resulting Cursor. See http://developer.android.com/reference/android/database/Cursor.html
For example, if you want the type of data for a column, you can use the getType() method in the newer versions of Android, or use a series of "get" functions to determine at least what type is readable, with this horrible code:
Cursor curs = db.rawQuery(sqlStr, null);
int numberOfColumns = curs.getColumnCount();
String []colNames = new String[numberOfColumns];
String []colTypes = new String[numberOfColumns];
for(int iCol=1; iCol<=numberOfColumns; iCol++) {
colNames[iCol-1] = curs.getColumnName(iCol-1);
colTypes[iCol-1] = null; //curs.getType(iCol);
}
while(curs.moveToNext()) {
// this code assumes that the first row has the same data types
// as the rest of the rows
for(int iCol=1; iCol<=numberOfColumns; iCol++) {
String colName = colNames[iCol-1];
String colType = colTypes[iCol-1];
if(colType==null) {
// determine column type
try {
curs.getString(iCol-1);
colType = colTypes[iCol-1] = "text";
} catch (Exception ignore) {
try {
curs.getLong(iCol-1);
colType = colTypes[iCol-1] = "integer";
} catch (Exception ignore1) {
try {
curs.getFloat(iCol-1);
colType = colTypes[iCol-1] = "real";
} catch (Exception ignore2) {
try {
curs.getBlob(iCol-1);
colType = colTypes[iCol-1] = "blob";
} catch (Exception ignore3) {
colType = colTypes[iCol-1] = "other";
}
}
}
}
}
if("text".equals(colType)) {
... curs.getString(iCol-1);
} else
if("real".equals(colType)) {
... curs.getDouble(iCol-1);
} else
if("integer".equals(colType)) {
... curs.getInt(iCol-1);
} else { // unknown type
... colType+"-"+curs.getString(iCol-1);
}
}
}
Other information is available in a similar manner, depending on your need.