What am I missing in this code? It shows me only the first record from the database and does not move to the next record.
Next button:
if (v.getId() == R.id.btnNext) {
try {
pos++;
database.Open();
Houes h = new Houes();
database.Shows(h, pos);
txNo.setText("" + h.getHouse_id());
txAdd.setText("" + h.getHouse_address());
txOn.setText("" + h.getHouse_owner());
txVal.setText("" + h.getHouse_value());
txDis.setText("" + h.getHouse_discount());
database.Close();
} catch (Exception e) {
}
database class:
protected void Shows(Houes house , int p ) {
// String[] columns = {house_id, house_address, house_owner, house_value, house_discount};
Cursor c = db.rawQuery("select * from " + database_table, null);
int iRow = c.getColumnIndex(house_id);
int iAdd = c.getColumnIndex(house_address);
int iOwn = c.getColumnIndex(house_owner);
int iVal = c.getColumnIndex(house_value);
int iDis = c.getColumnIndex(house_discount);
if(p==1){
c.moveToFirst();
}else if(p>1&&c.isAfterLast()==false){
c.moveToNext();
}
house.setHouse_id(c.getInt(iRow));
house.setHouse_address(c.getString(iAdd));
house.setHouse_owner(c.getString(iOwn));
house.setHouse_value(c.getInt(iVal));
house.setHouse_discount(c.getInt(iDis));
}
Change Shows to return the cursor that it extracts an do nothing else e.g.
Cursor Shows() {
return Cursor c = db.rawQuery("select * from " + database_table, null);
}
call the shows method before and outside of the next button click listener and also display the first house values after something along the lines of :-
cursor = db.shows();
if (cursor.moveToFirst()) {
int iRow = c.getColumnIndex(house_id); //etc
} else {
//handle no houses to show
}
......
within your next button listener
if (cursor.moveToNext) {
//do you stuff here
} else {
//handle end of rows here
}
previous button listener basically the same but uses moveToPrevious.
if you need to position to a specific house then loop through the cursor after it has been returned i.e. just move the existing code from Shows.
Make sure to do cursor.close(); when you have finished accessing the cursor.
Related
I'm getting many time repeating data from Sqlite / Android database. I want to get recode without repeating in Android cursor.
Here's my query:
public Cursor getQuizQuiestion(String cat, String level, String questionNo) {
String QUERY_SELECT_QUIESTION = "SELECT * FROM " +TABLE_QUIESTION +" WHERE "+COL_CAT+ " = '" +cat+"' AND "
+COL_LEVEL+ " = " +level+" ORDER BY RANDOM() LIMIT 1";
Cursor cursor = db.rawQuery(QUERY_SELECT_QUIESTION, null);
return cursor;
}
I Have Simple Example if I Used In My Project I think MayBe IT's Help You;
public ArrayList<ModelRandomList> getRandomData(String city){
ArrayList<ModelRandomList> modelRandomListArrayListLists = new ArrayList<ModelRandomList>();
String queryRandomData ="SELECT DISTINCT * FROM "+TABLE_NAME+" WHERE "+COL_CITY + "=?"+ "Order BY RANDOM()";
Cursor cursor = db.rawQuery(queryRandomData,new String[] { String.valueOf(city) });
if(cursor.getCount() != 0){
while (cursor.moveToNext()){
/*mName =cursor.getString(0);
mCity = cursor.getString(1);
Log.d(TAG,mName +" City "+mCity );*/
ModelRandomList modelRandomList = new ModelRandomList();
modelRandomList.setUserName(cursor.getString(0));
modelRandomList.setUserCity(cursor.getString(1));
modelRandomListArrayListLists.add(modelRandomList);
}
Random random = new Random();
Collections.shuffle(modelRandomListArrayListLists,random);
}
Log.d(TAG, "Get Random Totla No of Recode Found "+cursor.getCount());
return modelRandomListArrayListLists;
}
and in Your Activity
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private SqlLiteDataBaseHelper sqlLiteDataBaseHelper;
private Button btGetRandomData;
private ArrayList<ModelRandomList> modelRandomLists;
private Button btSingleRandomData;
private int position = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
modelRandomLists = new ArrayList<ModelRandomList>();
sqlLiteDataBaseHelper = new SqlLiteDataBaseHelper(MainActivity.this);
try{
if(sqlLiteDataBaseHelper.checkDataBase()){
Log.e(TAG, "Data Base Already Exists");
}else {
sqlLiteDataBaseHelper.CopyDataBaseFromAsset();
}
sqlLiteDataBaseHelper.openDataBase();
try {
Log.e(TAG, "No Of Racode In DataBase " + sqlLiteDataBaseHelper.getDataCount());
}catch (Exception e){
e.printStackTrace();
}
}catch (Exception e){
e.printStackTrace();
}
init();
}
private void init() {
btGetRandomData = (Button)findViewById(R.id.btRandomData);
btSingleRandomData = (Button)findViewById(R.id.btSingleRandomData);
}
#Override
protected void onResume() {
super.onResume();
btGetRandomData.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
modelRandomLists = sqlLiteDataBaseHelper.getRandomData("A");
for (ModelRandomList crt : modelRandomLists) {
Log.e(TAG, " " + crt.getUserName());
Log.e(TAG, " " + crt.getUserCity());
}
}
});
btSingleRandomData.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
try{
Log.d(TAG,modelRandomLists.get(position).getUserName());
position ++;
}catch (Exception e){
e.printStackTrace();
position =0;
}
}
});
}
}
You would have to keep a track of what questions have been seen before. What about this:
private List<Integer> seenQuestions = new ArrayList<>();
public Cursor getUseenQuizQuestion(String cat,String level,String questionNo) {
Cursor cursor = getQuizQuiestion(cat, level, questionNo);
while(cursor == null) { // This could be an infinite loop!!
cursor = getQuizQuiestion(cat, level, questionNo);
}
return cursor;
}
private Cursor getQuizQuiestion(String cat,String level,String questionNo){
String QUERY_SELECT_QUIESTION = "SELECT * FROM " +TABLE_QUIESTION +" WHERE "+COL_CAT+ " = '" +cat+"' AND "
+COL_LEVEL+ " = " +level+" ORDER BY RANDOM() LIMIT 1";
Cursor cursor = db.rawQuery(QUERY_SELECT_QUIESTION, null);
if(cursor.moveToFirst()) {
int resultId = cursor.getString(cursor.getColumnIndexOrThrow("_id"));
if(seenQuestions.contains(resultId)) {
cursor.close();
return null;
}
seenQuestions.add(resultId);
}
return cursor;
}
^ the code sample above has many flaws and could loop infinitely.
But the point is you need to keep track of what has been returned and query again if you have seen it.
Alternatively, you could allow your DB query to return all data and then use a Random value to select one of the items.
There is no way to create unique results if you are querying over and over again.
Since you are not using the questionNo parameter and return a cursor anyway: why not just remove the limit 1 and add the distinct clause to your statement?
If you do it that way, you can use your cursor to iterate over the unique questions:
String QUERY_SELECT_QUIESTION = "SELECT DISTINCT * FROM " +TABLE_QUIESTION +" WHERE "+COL_CAT+ " = '" +cat+"' AND "
+COL_LEVEL+ " = " +level+" ORDER BY RANDOM()";
Then you can iterate over the questions until you have none or whatever your conditions are:
Cursor cursor = db.rawQuery(QUERY_SELECT_QUIESTION, null);
try {
while (cursor.moveToNext()) {
//display question or copy them to a member or whatever
}
} finally {
cursor.close();
}
I'm trying to load a database column with a cursor result for my quiz app. The reason for this is that i want to populate a list view with the questions in a each category so i set up this:
public void putValues(){
for (int i = 0; i < 18; i++) {
Cursor contentCursor = null;
contentCursor = mDB
.rawQuery("select count(*) from questions_en where used = 0 and category" + " = " + i, null);
if(contentCursor.getCount() >0 )
contentCursor.moveToFirst();
if (contentCursor.isAfterLast()) {
contentCursor.close();
mDB.close();
return;
}
int contentCursorInt = contentCursor.getInt(0);
Cursor upateCursor = null;
upateCursor = mDB.rawQuery("update categories_en set questions_count" + " = " + contentCursorInt + " where " + "_id" + " = " + i, null);
upateCursor.moveToNext();
upateCursor.close();
contentCursor.close();
}
}
so that when the user clicks an answer (on the question screen) used becomes 1(or any non-zero value) the query result changes. The above code works fine the very first time. Because i haven't set up the question screen, i added this query:
public void test(){
Cursor cus = mDB.rawQuery("update questions_en set used = 1 where category = 2 and _id = 146", null);
cus.close();
}
to my DB Adapter and then called this method from my MainActivty
#Override
public void onClick(View v) {
TestAdapter mTest = new TestAdapter(MainActivity.this);
mTest.createDatabase();
mTest.open();
mTest.test();
Log.d(DBHelper.TAG, " Worked ");
mTest.close();
}
});
But when i click on this and go to my ListActivity I expected the value of category 2 to have changed since the query had just been carried out again. But it doesn't reduce. I pulled out my DB from DDMS(file explorer) and i found out that the query to _id = 146 actually didn't change used to 1. Any help on what may be the cause?
Solve the problem with the help of this.
I just changed this:
public void test(){
Cursor cus = mDB.rawQuery("update questions_en set used = 1 where category = 2 and _id = 146", null);
cus.close();
}
to this
public void test(){
int id = 3;
ContentValues data = new ContentValues();
data.put(DBHelper.KEY_USED, "1");
mDB.update(DBHelper.KEY_QUESTIONS_TABLE, data, DBHelper.KEY_ID + " = " + id , null);
}
//How to iterate using cursor.moveToPosition(x) when Onclick of Random and NextTORandom Button is clicked?
//here is my code for Mydatabase.java. This file is used to fetch the single row from the database.
public Cursor getData(int _id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor =db.rawQuery("Select * from '"+DB_TABLE+"' where _id = ?", new String[] { String.valueOf(_id)});
if (cursor != null)
{
cursor.moveToFirst();
}
return cursor;
// here is my code for MyActivity.java
public void onClick(View v) {
cur=db.getData(position);
int firstpos=1;
int lastpos=4;
switch(v.getId())
{
case R.id.NextToRandom :
{
if (cur != null && cur.getCount()> 0 && position < cur.getCount() && position != cur.getCount()){
cur.moveToPosition(position);
textView1.setText(""+cur.getString(1));// Display Columns
position++;
cur.moveToNext();
}
if(cur.moveToPosition(lastpos))
{
cur.moveToPosition(firstpos);
textView1.setText(""+cur.getString(1));
}
/*else
{
cur.moveToPosition(position);
textView1.setText(""+cur.getString(1));
position++;
}*/
//display details code
}
break;
case R.id.random:
{
Random r = new Random();
int rnum = r.nextInt(max - min + 1) + min;
cur=db.getData(rnum);
setNewData(rnum);
}
}
}
private void setNewData (int xyz) {
}
//I want to loop through all the records by clicking Random_back_button,Random_button and Random_Next_button. How to implement this?
You can iterate over a cursor like so:
Cursor cursor = ...; // get cursor from somewhere
for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext) {
// your code here
}
Cursors do provide random access, so if you need to access a particular row, call cursor.moveToPosition(int).
Official Code here ↓↓↓↓↓↓↓↓↓↓↓↓↓↓
// ------------------------------
// android.database.DatabaseUtils
// ------------------------------
public static void dumpCursor(Cursor cursor, StringBuilder sb) {
sb.append(">>>>> Dumping cursor " + cursor + "\n");
if (cursor != null) {
int startPos = cursor.getPosition();
cursor.moveToPosition(-1);
while (cursor.moveToNext()) {
dumpCurrentRow(cursor, sb);
}
cursor.moveToPosition(startPos);
}
sb.append("<<<<<\n");
}
I'm messing around with some SQLite databases for an Android app. I have a 'player' table with several players, and a one-to-many 'skill' table which has each player's skill points, like Shooting and Rebounding.
I have one activity in the app for actually filling out textboxes and inserting a player into the database. When the user hits the 'Add Player' button, a row is inserted into the 'player' table and a row is inserted into the 'skills' table which has a foreign key that references the 'player' table. After these inserts, I did a query to check if I could read the 'Shooting' value from the 'skills' table and put it in a Toast notification. That worked fine, and the code I used is here:
SQLiteDatabase db2 = dbHelper.getReadableDatabase();
String[] projection = { "shooting" };
String sortOrder = "shooting" + " DESC";
Cursor c = db2.query(
"skills", // The table to query
projection, // The columns to return
null, // The columns for the WHERE clause
null, // The values for the WHERE clause
null, // don't group the rows
null, // don't filter by row groups
sortOrder // The sort order
);
c.moveToFirst();
int shooting = c.getInt(c.getColumnIndexOrThrow("shooting"));
Toast.makeText(this, "" + shooting, Toast.LENGTH_SHORT).show();
After I saw that this was working, I commented it out and put in an Intent to make the app switch to the 'Roster' activity after the player and skills are inserted. On the 'Roster' activity, I want to get each player's 'Shooting' skill. When I use the exact same code from above (which works from the other activity) I get an error which says:
06-16 15:59:42.602: E/AndroidRuntime(31537): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.silverray.messaround/com.silverray.messaround.Roster}: java.lang.IllegalArgumentException: column 'shooting' does not exist
I can't figure out why it's saying the 'shooting' column doesn't exist when I know I included it in my SQL Create statement, and I was even able to read this exact same column with the same code from another activity.
Thanks for reading. Any ideas?
EDIT: This is the full code for the Roster activity:
public class Roster extends Activity {
int teamID = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_roster);
// CHECK ROSTER
DatabaseContract dbContract = new DatabaseContract();
DatabaseContract.DbHelper dbHelper = dbContract.new DbHelper(this);
SQLiteDatabase dbCheck = dbHelper.getReadableDatabase();
Intent intent = getIntent();
int ID = intent.getIntExtra("ID", 1);
teamID = ID;
String stringID = String.valueOf(ID);
String[] projection = { "_id, playerFirstName, playerLastName, playerPosition" };
String sortOrder = "playerFirstName" + " ASC";
Cursor c = dbCheck.query(
"player",
projection,
null,
null,
null,
null,
sortOrder
);
c.moveToFirst();
int rowsAffected = c.getCount();
if (rowsAffected < 1) {
TextView rosterList = (TextView) findViewById(R.id.txtListRoster);
rosterList.setText("Your team doesn't have any players!");
c.close();
dbCheck.close();
} else {
String players = "";
for (int l = 0; l < rowsAffected; l++) {
String playerName = c.getString(c.getColumnIndexOrThrow("playerFirstName"));
String playerLastName = c.getString(c.getColumnIndexOrThrow("playerLastName"));
String position = c.getString(c.getColumnIndexOrThrow("playerPosition"));
int playerID = c.getInt(c.getColumnIndexOrThrow("_id"));
String player_ID = String.valueOf(playerID);
String pos = "";
if (position.equals("Point Guard")) {
pos = "PG";
} else if (position.equals("Shooting Guard")) {
pos = "SG";
} else if (position.equals("Small Forward")) {
pos = "SF";
} else if (position.equals("Power Forward")) {
pos = "PF";
} else if (position.equals("Center")) {
pos = "C";
}
SQLiteDatabase db2 = dbHelper.getReadableDatabase();
String[] projection2 = { "shooting" };
String sortOrder2 = "shooting" + " DESC";
Cursor c2 = db2.query(
"skills",
projection2,
null,
null,
null,
null,
sortOrder2
);
c2.moveToFirst();
//** Everything works until this line:
int shooting = c2.getInt(c.getColumnIndexOrThrow("shooting"));
players += playerName + " " + playerLastName + " (" + pos + ") Shooting: ";
if (l != (rowsAffected - 1)) {
players += "\n";
}
TextView rosterList = (TextView) findViewById(R.id.txtListRoster);
rosterList.setText(players);
if (l != (rowsAffected - 1)) {
c.moveToNext();
}
c2.close();
}
c.close();
dbCheck.close();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.roster, menu);
return true;
}
public void addPlayer(View view) {
Intent goToAddPlayer = new Intent(this, AddPlayer.class);
goToAddPlayer.putExtra("ID", teamID);
this.startActivity(goToAddPlayer);
this.finish();
return;
}
}
int shooting = c2.getInt(c.getColumnIndexOrThrow("shooting"));
should be
int shooting = c2.getInt(c2.getColumnIndexOrThrow("shooting"));
You are now working on 2nd query but trying to get column index from 1st.
I have two buttons inside of my application, one for next and one for prev. I want the next button to get the next record inside of my database and display it inside of my view, and the prev button to get the previous record and display it inside of my view. How would I call the next or previous record? I have looked for tutorials and stuff but didn't find any. I anyone has a tutorial please share with me. Thanks for any help. I wish I had some code to provide but I really don't know where to start.
I use an int to pull the record from the dbase.
From my ContactView class
static long record = 1;
public void getData() {
DBase db = new DBase(this);
db.open();
lastRecord = db.lRec();
firstRecord = db.fRec();
rRec = db.getRec(record);
db.close();
}
then my query is from my Dbase class
public String[] getRec(long record) {
record = ContactView.record;
String[] columns = new String[] { KEY_ROWID, KEY_ONE, KEY_TWO,
KEY_THREE, KEY_FOUR, KEY_FIVE, KEY_SIX };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "="
+ record, null, null, null, null);
if (c != null && c.moveToFirst()) {
String rRec = c.getString(0);
String rOne = c.getString(1);
String rTwo = c.getString(2);
String rThree = c.getString(3);
String rFour = c.getString(4);
String rFive = c.getString(5);
String rSix = c.getString(6);
String[] rData = { rRec, rOne, rTwo, rThree, rFour,
rFive, rSix };
return rData;
}
return null;
}
and the next few are from my ContactView class
my buttons
#Override
public void onClick(View arg0) {
switch (arg0.getId()) {
case R.id.bSQLvPrev:
recordMinus();
display();
break;
case R.id.bSQLvNext:
recordPlus();
display();
break;
}
}
and the methods they call
public void display() {
etSQLvRec.setText(rRec[0]);
etSQLvOne.setText(rRec[1]);
etSQLvTwo.setText(rRec[2]);
etSQLvThree.setText(rRec[3]);
etSQLvFour.setText(rRec[4]);
etSQLvFive.setText(rRec[5]);
etSQLvSix.setText(rRec[6]);
}
public void recordPlus() {
record++;
}
public void recordMinus() {
record--;
}
That will get the record from the database based on the "record" variable, and the buttons increment it, or decrement it, it also skips any "empty" records.
EDIT OK, I had changed some stuff around since I lasted used my db, so use the next recordPlus() and recordMinus() code instead
public void recordPlus() {
if (record < lastRecord) {
record++;
} else {
record = firstRecord;
}
getData();
do {
if (record < lastRecord) {
record++;
} else {
record = firstRecord;
}
getData();
} while (rRec == null);
}
public void recordMinus() {
if (record == 1) {
record = lastRecord;
} else {
record--;
}
getData();
do {
if (record == 1) {
record = lastRecord;
} else {
record--;
}
getData();
} while (rRec == null);
}
And you'll need my fRec() and lRec() which find the first and last records in the DB
public long fRec() {
Cursor c = ourDatabase.query(DATABASE_TABLE, new String[] { "min(" +
KEY_ROWID
+ ")" }, null, null, null, null, null);
c.moveToFirst();
long rowID = c.getInt(0);
return rowID;
}
}
public long lRec() {
long lastRec = 0;
String query = "SELECT ROWID from Table order by ROWID DESC limit 1";
Cursor c = ourDatabase.rawQuery(query, null);
if (c != null && c.moveToFirst()) {
lastRec = c.getLong(0);
}
return lastRec;
}