I have the following function in android studio, which is supposed to return a sqlite cursor.
The problem comes in the selectionArgs argument. Whenever I am passing more than one value to it, it returns a cursor with 0 records.
public Cursor getCursor(String strListWhere, String strTable, String strCols) {
String strColsToReturn = mySqliteHandler.getWhereColNamesFromJsonString(strListWhere);
String strArgs = mySqliteHandler.getWhereColArgsFromJsonString(strListWhere);
Log.d(TAG, "qqqq9: " + strArgs);
String strTableName = strTable;
String[] strColumnsToReturn = { strCols };
String strSelectWhere = strColsToReturn ;
String[] strSelectArgs = { strArgs };
Cursor csrResult = sqLiteDatabase.query(true, strTableName, strColumnsToReturn, strSelectWhere, strSelectArgs, null, null, null, null);
Log.d(TAG, "qqqq9: " + csrResult.getCount());
return csrResult;
}
The value in strColsToReturn is animal_class = ? and province_name = ?
The value in strArgs is Bird, KwaZulu-Natal
So I want it to be animal_class = 'Bird' and province_name = 'KwaZulu-natal'
When I only pass one value it works, for example
The value in strColsToReturn is animal_class = ?
The value in strArgs is Bird
Can anyone assist?
EDIT: the following code works:
public Cursor getCursor(String strListWhere, String strTable, String strCols) {
String strColsToReturn = mySqliteHandler.getWhereColNamesFromJsonString(strListWhere);
List<String> arrWhere = new ArrayList<String>();
arrWhere = mySqliteHandler.getWhereArray(strListWhere);
String[] finalValue = new String[ arrWhere.size() ];
arrWhere.toArray( finalValue );
String strTableName = strTable;
String[] strColumnsToReturn = { strCols };
String strSelectWhere = strColsToReturn ;
Cursor csrResult = sqLiteDatabase.query(true, strTableName, strColumnsToReturn, strSelectWhere, finalValue, null, null, null, null);
return csrResult;
}
The value for strColumnsToReturn should be an array with the names of the columns that you want returned, like:
new String[] {column1, column2, column3}
where column1, column2, column3 are strings.
The value for strSelectWhere should be the string:
"animal_class = ? and province_name = ?"
and the value of strSelectArgs should be a string array with the parameters that you pass to each of the ? placeholders of strSelectWhere:
new String {"Bird", "KwaZulu-Natal"}
You can find more here
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I cannot understand this problem. I have tried to get the solution from other stackoverflow questions but failed to get the solution. I was not getting this error before. However, now I don't know what's wrong with the code stated below. Please help me with this. I'm stuck with this problem.
public void getAlbumsLists() {
final Uri uri = MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI;
final String _id = MediaStore.Audio.Albums._ID;
final String album = MediaStore.Audio.Media.ALBUM;
final String album_name = MediaStore.Audio.AlbumColumns.ALBUM;
final String artist = MediaStore.Audio.AlbumColumns.ARTIST;
final String tracks = MediaStore.Audio.AlbumColumns.NUMBER_OF_SONGS;
// final String data=MediaStore.Audio.Albums.ALBUM_ID; // NO
// final String id1=MediaStore.Audio.Albums.ALBUM_ID;
final String tit = MediaStore.Audio.Albums.ALBUM; //NO
final String nam = MediaStore.Audio.Albums.ALBUM_KEY; // NO
final String typ = MediaStore.Audio.Media.MIME_TYPE; // NO
final String art = MediaStore.Audio.Albums.ALBUM_ART; //<<<< CAN GET
final String artstkey = MediaStore.Audio.Artists.ARTIST_KEY; //<<<< CAN GET
final String frstyr = MediaStore.Audio.AlbumColumns.FIRST_YEAR; //<<<< CAN GET
final String lstyr = MediaStore.Audio.AlbumColumns.LAST_YEAR; //<<<< CAN GET
final String artstid = "artist_id"; //<<<< CAN GET
final String[] columns = {"*"};
Cursor cursor = getActivity().getContentResolver().query(uri, columns, null, null, null);
// Lists the columns in the cursor
for (String s : cursor.getColumnNames()) {
Log.d("COLUMNS", "Column = " + s);
}
while (cursor.moveToNext()) {
String id = (cursor.getString(cursor.getColumnIndex(_id)));
String name = cursor.getString(cursor.getColumnIndex(album_name));
String artist2 = cursor.getString(cursor.getColumnIndex(artist));
String nr = cursor.getString(cursor.getColumnIndex(tracks));
String x = (cursor.getString(cursor.getColumnIndex(album)));
//String data1=cursor.getString(cursor.getColumnIndexOrThrow(data)); //<<<< NOT A COLUMN
// String id2=cursor.getString(cursor.getColumnIndex(data));
//String title=cursor.getString(cursor.getColumnIndex(tit)); //<<<< NOT A COLUMN
//String name1=cursor.getString(cursor.getColumnIndex(nam)); //<<<< NOT A COLUMN
//String type=cursor.getString(cursor.getColumnIndex(typ)); //<<<< NOT A COLUMN
// AVAIALABLE COLUMNS
String artwork = cursor.getString(cursor.getColumnIndex(art)); //<<<< ADDED
String artistkey = cursor.getString(cursor.getColumnIndex(artstkey)); //<<<< ADDED
String artistid = cursor.getString(cursor.getColumnIndex(artstid)); //<<<< ADDED
String minyear = cursor.getString(cursor.getColumnIndex(frstyr));
String maxyear = cursor.getString(cursor.getColumnIndex(lstyr));
s = new albumInfo(id, name, artist2, nr, artwork, x); // EXCLUDED
albumList.add(s);
cursor.close();
recyclerView1.setAdapter(albumAdapter); // EXCLUDED
}
}
Move cursor.close(); outside the while loop.
Edited..
First time after the while loop iterates the cursor is closed so you need to put it outside while.
I can suggest three improvement scenarios.
You need to move the cursor to first before accessing it for fetching data from the cursor.
You need to close the cursor when nothing is returned or the cursor is null.
Move the cursor close outside of your while loop.
So I would like to recommend you to rewrite the code like following.
// After you have fetched the data from cursor
if(cursor == null) return;
if(cursor.size() == 0) {
cursor.close();
return;
}
for (String s : cursor.getColumnNames()) {
Log.d("COLUMNS", "Column = " + s);
}
// Move the cursor to the first position.
cursor.moveToFirst();
do {
String id = (cursor.getString(cursor.getColumnIndex(_id)));
String name = cursor.getString(cursor.getColumnIndex(album_name));
String artist2 = cursor.getString(cursor.getColumnIndex(artist));
String nr = cursor.getString(cursor.getColumnIndex(tracks));
String x = (cursor.getString(cursor.getColumnIndex(album)));
// ... Other code
} while (cursor.moveToNext());
recyclerView1.setAdapter(albumAdapter); // EXCLUDED
// Move the cursor outside of while loop
cursor.close();
I have created two string variables, 'questionString' and 'answerSetId' - the first of which I have assigned to a textview - the second of which I would like to pass to my db helper class:
public void showNextRandomQuestion3() {
SQLDatabaseHelper db = new SQLDatabaseHelper(this);
//get the data from the database
List<List<String>> listList = db.getAllAnswersByQuestion1();
//Get the question/text/answer Strings
List<String> questionStrings = listList.get(0); //question Strings
List<String> answerSetIds = listList.get(4);
//Generate random index
Random r = new Random();
int rand = Math.abs((r.nextInt() % questionStrings.size()));
//get answer description for randomly selected question
String questionString = questionStrings.get(rand);
String answerSetId = answerSetIds.get(rand);
questionView.setText(questionString);
}
In my db helper class, I want to use this string variable as pat of my query:
public List<List<String>> getAnswers() {
List<String> array1 = new ArrayList<String>();
List<String> array2 = new ArrayList<String>();
SQLiteDatabase db = this.getReadableDatabase();
String selectQuery = "SELECT * FROM " + TABLE_ANSWERS + "WHERE " + ASID
+ " = " + ??answerSetId??;
Cursor c = db.rawQuery(selectQuery, null);
if (c.moveToFirst()) {
do {
String textdescr = c.getString(c.getColumnIndex(TDESCR));
String answersdescr = c.getString(c.getColumnIndex(ADESCR));
array1.add(textdescr);
array2.add(answersdescr);;
} while (c.moveToNext());
}
List< List<String> > listArray2 = new ArrayList< List<String> >();
listArray2.add(array1);
listArray2.add(array2);
return listArray2;
}
What would be the best way to achieve this?
In order to perform a SELECT, you can use this method
query(String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy)
instead of raw query. In your case:
String selection = ASID+"=?";
String selectionArgs[] = new String[]{String.valueOf(answerSetId)};
Cursor c = db.query(TABLE_ANSWERS, null, selection, selectionArgs, null, null, null);
You can also select some specific columns, passing a list of columns name as second parameter (insted of null). Also, you can replace the last three null value in the example for adding the GROUP BY, HAVING and ORDER BY clauses.
For example, in your query you are interested only in the two columns TDESCR and ADESCR. So you could use this query:
String[] columns = new String[]{TDESCR, ADESCR};
String selection = ASID+"=?";
String[] selectionArgs = new String[]{String.valueOf(answerSetId)};
Cursor c = db.query(TABLE_ANSWERS, columns, selection, selectionArgs, null, null, null);
There are a lot of others override methods query. Take a look at the documentation here
However, if you prefer you can perform a raw query in this way:
String queryString = "SELECT * FROM " + TABLE_ANSWERS +
" WHERE "+ASID+"=?";
String[] selectionArgs = new String[]{String.valueOf(answerSetId)};
sqLiteDatabase.rawQuery(queryString, selectionArgs);
Hi I am creating an sqlite helper file for my android project. I have found a couple of tutorials on doing this but i am having an issue with retrieving values from the sqlite database. I get the following error message:"Can not resolve constructor"
Event getEvent(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_EVENTS, new String[] { KEY_ID, KEY_EVENTNAME, KEY_EVENTTIME,
KEY_EVENTDATE, KEY_EVENTLOCATION, KEY_EVENTADDRESS1, KEY_EVENTADDRESS2, KEY_EVENTCITY, KEY_EVENTSTATE, KEY_EVENTZIP, KEY_EVENTTYPE },
KEY_ID + "=?", new String[] {String.valueOf(id)}, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Event event = new Event(Integer.parseInt(cursor.getString(0)), cursor.getString(1),cursor.getString(2),cursor.getString(3),cursor.getString(4),
cursor.getString(5), cursor.getString(6),cursor.getString(7), cursor.getString(8), cursor.getString(9),
cursor.getString(10), cursor.getString(11));
//return event
return event;
}
The error is in the statement that starts with Event event = new Event....
I am not sure do if i need a cursor.getString(n) for each table column?
Any help would be great.
Thanks.
adding event file
//empty contructor
public Event(){
}
public Event(int id, String _eventName, String _eventTime, String _eventDate, String _eventLocation, String _eventAddress1, String _eventAddress2, String _eventCity, String _eventState, int _eventZip, String _eventType) {
this._id = id;
this._eventName = _eventName;
this._eventTime = _eventTime;
this._eventDate = _eventDate;
this._eventLocation = _eventLocation;
this._eventAddress1 = _eventAddress1;
this._eventAddress2 = _eventAddress2;
this._eventCity = _eventCity;
this._eventState = _eventState;
this._eventZip = _eventZip;
this._eventType = _eventType;
}
public Event(String _eventName, String _eventTime, String _eventDate, String _eventLocation, String _eventAddress1, String _eventAddress2, String _eventCity, String _eventState, int _eventZip, String _eventType) {
this._eventName = _eventName;
this._eventTime = _eventTime;
this._eventDate = _eventDate;
this._eventLocation = _eventLocation;
this._eventAddress1 = _eventAddress1;
this._eventAddress2 = _eventAddress2;
this._eventCity = _eventCity;
this._eventState = _eventState;
this._eventZip = _eventZip;
this._eventType = _eventType;
}
Thanks #Selvin and #Pier That was part of the issue I had too many parameters and the other part was I didn't realize that you need cursor.getInt() instead cursor.getString for integers.
Thanks again
I have a page which can retrieve user data from database
but after whole day of trying, I am only able to get the table column name but not the value inside.
this is my code to create database
public static final String LASTLOGIN = "lastuser";
public static final String USER_ID = "suser_id";
public static final String USER_NAME = "suser_name";
public static final String USER_PASSWORD = "spassword";
public static final String PRIME_ID = "id";
private static final String TABLE_USER =
"create table "+ LASTLOGIN+" ("
+PRIME_ID+" integer primary key autoincrement, "
+ USER_ID + " text, "
+ USER_NAME +" text, "
+USER_PASSWORD+" text); ";
and here is the function implemented to get user data
public Cursor getuser()
{
String[] columns = new String[]{PRIME_ID, USER_NAME, USER_PASSWORD};
Cursor cursor = sqLiteDatabase.query(
LASTLOGIN, columns, null, null, null, null, PRIME_ID +" DESC");
Log.d("TAG", columns[1]);
return cursor;
}
and here is my code to display the result
mySQLiteAdapter = new SQLiteAdapter(this);
mySQLiteAdapter.openToWrite();
cursor = mySQLiteAdapter.getuser();
String[] resultvalue = new String{
SQLiteAdapter.PRIME_ID,SQLiteAdapter.USER_NAME, SQLiteAdapter.USER_PASSWORD};
Toast.makeText(this, resultvalue[0]+resultvalue[1], Toast.LENGTH_LONG).show();
and the toast result only show the column name but not the value inside, is there any mistake i made? and I want to set limit to 1, but where to set it?
Thanks for helping me
the way you try reading the values is completly wrong.
you create an array
String[] resultvalue = new String[]{
SQLiteAdapter.PRIME_ID,
SQLiteAdapter.USER_NAME,
SQLiteAdapter.USER_PASSWORD};
after that you read the values 0 and 1 from this array.
Your toast works absolutly correctly becouse inside this array you define the column names!
If you want to show the values from your query do it this way:
while(cursor.moveToNext()){
Integer str1 = str 1 + cursor.getInteger(1);
String str2 =str2 + cursor.getString(2);
Toast.makeText(this, str1 + str2, Toast.LENGTH_LONG).show();
}
or a better way receiving the correct index:
cursor.getInteger( cursor.getColumnIndex(SQLiteAdapter.PRIME_ID) );
cursor.getString( cursor.getColumnIndex(SQLiteAdapter.USER_NAME) );
Please note when retrieving data from a database, you store it in a Cursor in the memory and hence can only access it using that particular Cursor object, which you have used in the following line of code.
Cursor cursor = mySQLiteAdapter.getuser();
The Following line retrieves the column names and not the values.
String[] resultvalue = new String[]{SQLiteAdapter.PRIME_ID,SQLiteAdapter.USER_NAME, SQLiteAdapter.USER_PASSWORD};
So the following is doing what you have asked it to do, retrieve column names not values
Toast.makeText(this, resultvalue[0]+resultvalue[1], Toast.LENGTH_LONG).show();
You need something like following:
if(cursor.getCount() != 0)
{
while(cursor.moveToNext())
{
resultvalue [0] = csr.getString(0);
resultvalue [1] = csr.getString(1);
//....
}
}
Hope this helps
here is my solution:
final String TABLE_NAME = "table_name";
String selectQuery = "SELECT Column FROM "+TABLE_NAME+" WHERE column='"+some_value+"'";
SQLiteDatabase db = this.openDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
String[] data = new String[cursor.getCount()];;
int i = 0;
if (cursor.moveToFirst()) {
do {
i=Integer.parseInt(cursor.getString(cursor.getColumnIndex("value")));
} while (cursor.moveToNext());
}
cursor.close();
I'm developing an Android 3.1 application.
I have the following tables:
FormBlock
---------
FormId (INTEGER) FOREIGN KEY TO Form.id
BlockId (INTEGER) FOREIGN KEY TO Block.id
Block
----------
id (INTEGER) PRIMARY KEY
name (TEXT) NOT NULL
orderInForm (INTEGER) NOT NULL
And I want to do the following select:
SELECT block.blockId, block.name, block.orderInForm FROM Block, FormBlock WHERE FormBlock.FormId = 1 AND block.blockId = FormBlock.blockId;
How can I do that select statement with SQLiteDatabase.query(...) or rawQuery()?
SELECT
block.blockId, block.name, block.orderInForm
FROM
Block, FormBlock
WHERE
FormBlock.FormId = 1 AND block.blockId = FormBlock.blockId;
as query is
String table = "Block, FormBlock";
String[] columns = new String[] { "block.blockId", "block.name", "block.orderInForm" };
String where = "FormBlock.FormId = 1 AND block.blockId = FormBlock.blockId";
Cursor result = db.query(table, columns, where, null, null, null, null);
if the 1 is dynamic then
int formId = 1;
String table = "Block, FormBlock";
String[] columns = new String[] { "block.blockId", "block.name", "block.orderInForm" };
String where = "FormBlock.FormId = ? AND block.blockId = FormBlock.blockId";
String[] whereArgs = new String[] { String.valueOf(formId) };
Cursor result = db.query(table, columns, where, whereArgs, null, null, null);
Try this:
String query = "SELECT * FROM Block WHERE id IN
(SELECT BlockId FROM FormBlock WHERE FormId = 1)";
Cursor c = database.rawQuery(query, null);