I have an SQLite Database in my android application with the following structure:
public void onCreate(SQLiteDatabase db) {
String CREATE_LISTS_TABLE = "CREATE TABLE " + TABLE_LISTS +
"("+
_ID + " INTEGER PRIMARY KEY , " +
NOTE + " TEXT" +
")";
db.execSQL(CREATE_LISTS_TABLE);
}
And this works, in that I can insert data into it without a problem. However I need to store the notes inside an array. I currently have the following query:
public List<String> getAllNotes() {
List<String> notes = new ArrayList<>();
String GET_ALL_NOTES = "SELECT * FROM " + TABLE_LISTS;
SQLiteDatabase db = getReadableDatabase();
if(db!=null)
{
Cursor cursor = db.rawQuery(GET_ALL_NOTES, null);
cursor.moveToFirst();
while(!cursor.isAfterLast())
{
notes.add(String.valueOf(cursor.getInt(cursor.getColumnIndex("notes"))));
cursor.moveToNext();
}
cursor.close();
}
db.close();
return notes;
}
However, this gives the following error:
java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
I was wondering how to fix this, I have read the android developer stuff but I can't seem to get anything to work.
Thanks in advance
Check the value of "NOTE", and use it in:
notes.add(String.valueOf(cursor.getInt(cursor.getColumnIndex(NOTE))));
I think a best way to make the call should be something like this:
// Check the cursor
if(cursor != null) {
if (cursor.moveToFirst()) {
// Variables to be used
String note;
// Col position
int colNote = cursor.getColumnIndex(NOTE);
do {
// Get the information
note = cursor.getString(colNote);
// Add the note
notes.add(note);
} while (cursor.moveToNext());
}
// Close the cursor
cursor.close();
}
Because you are fetching only integer and string from database, instead of using ArrayList , you can try using HashMap. So you can get the value by just giving the key. Below simple code will work for ArrayList too with minor changes..
Try this
HashMap<Integer,String> notes = new HashMap<Integer,String>() ;
Cursor cursor = db.rawQuery(GET_ALL_NOTES, null);
while (cursor.moveToNext())
{
int i = cursor.getInt(0);
String s = cursor.getString(1);
notes.put (i,s) ;
}
cursor.close();
Related
I am trying to return the names of distinct values in the 'category' column of an SQLite database. The cursor does not appear to be returning any results.
I'm building an Android app using a pre-existing database of bird species. The aim is to allow the user to explore the database through the app. The problem I'm having is in trying to return the distinct categories of bird species that exist in the database. The database appears to be opening successfully - no SQLite exception is being thrown, - but after using the query, the '.moveToNext' method does not appear to be returning any data.
public ArrayList<String> getCategory(String[] name){
String TABLE_BIRDS = "main";
String[] COLUMN = name;
ArrayList<String>categories = new ArrayList<>();
if (name[0]!=null)
{
Log.d(LOG_TAG, name[0]);
} else {
Log.d(LOG_TAG, "name[0] has not been passed");
}
x = db.query(true, TABLE_BIRDS, new String[] { COLUMN[0] } , null, null, COLUMN[0], null, null, null );
if (x.moveToNext()) {
Log.i(LOG_TAG, x.getString(x.getColumnIndex("category")));
}
else {
Log.i(LOG_TAG, "The cursor is not returning any data");
}
//Simple cursor loop
if (x.moveToNext()){
String category = new String();
category = x.getString(x.getColumnIndex(category));
categories.add(category);
Log.i("cursor loop", category);
}
return categories;
In the above code, the log messages are showing that: getCategory is receiving the expected string "category" before the query, but right after the query, the if/else loop is reporting that "The cursor is not returning any data".
What I expected is that the query would return six Strings, the cursor loop would add them to the ArrayList 'categories', and this ArrayList would be returned.
Please any help would be appreciated.
Here is a simpler version of your method:
public ArrayList<String> getCategory(String[] name) {
String TABLE_BIRDS = "main";
ArrayList<String> categories = new ArrayList<>();
if (name[0] != null) {
Log.d(LOG_TAG, name[0]);
} else {
Log.d(LOG_TAG, "name[0] has not been passed");
}
Cursor x = db.query(true, TABLE_BIRDS, new String[]{name[0]}, null, null, null, null, null, null);
while (x.moveToNext()) {
String category = x.getString(0);
categories.add(category);
Log.i("cursor loop", category);
}
if (x.getCount() == 0) {
Log.i(LOG_TAG, "The cursor is not returning any data");
}
x.close();
return categories;
}
I guess name[0] contains the string 'category' which is the column that you want to query.
Since you pass true as the 1st argument in the method query() this means that you will get distinct values, so no need for the group by argument.
You don't need the variable COLUMN since you have what you need in the variable name.Also you don't need getColumnIndex() since the cursor returns only 1 column.
Edit
Instead of:
Cursor x = db.query(true, TABLE_BIRDS, new String[]{name[0]}, null, null, null, null, null, null);
try rawQuery():
Cursor x = db.rawQuery("SELECT DISTINCT " + name[0] + " FROM " + TABLE_BIRDS, null);
Assuming the cursor is not null, you should
iterate over the results with a while/for loop.
e.g :while(x.moveToNext()) {
//your logic
}
It is always useful when debugging this kind of issues to install an SQLite DB browser then check the cursor's query against your DB to see if you have any data.
I have db table as follows
I want to update status column to 1 with id = 1,2,3.
For a single row I can update with content values
public void updateJobStatus(int callId) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues data = new ContentValues();
data.put(AppDBConstants.KEY_JOB_DETAIL_STATUS, 1);
db.update(AppDBConstants.TABLE_JOB_DETAIL, data, AppDBConstants.KEY_JOB_DETAIL_CALL_ID + "=" + callId, null);
db.close();
}
What to do for multiple rows?
Update Your query like this
db.update(AppDBConstants.TABLE_JOB_DETAIL, data, AppDBConstants.KEY_JOB_DETAIL_CALL_ID + " IN (?,?,?)", new String[]{"1","2","3"});
I think you current code is working for multiple id but need some of changes as below to achieve your requirement :
public void updateJobStatus(int[] callIds) {
SQLiteDatabase db = this.getWritableDatabase();
if (db != null) {
db.beginTransaction();
try {
for(int id : callIds){
ContentValues data = new ContentValues();
data.put(AppDBConstants.KEY_JOB_DETAIL_STATUS, 1);
db.update(AppDBConstants.TABLE_JOB_DETAIL, data, AppDBConstants.KEY_JOB_DETAIL_CALL_ID + "=" + id, null);
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
db.close();
}
}
Note : As above you need to pass id array it might be one or multiple.
When you have unknown number of arguments, try this one
String args = TextUtils.join(", ", arrayOfIds);
db.execSQL(String.format("UPDATE %s SET %s = true WHERE %s IN (%s);",
TABLE_INCOMING_MESSAGES, KEY_MESSAGE_SENT, KEY_ID, args));
I am new in Android Studio and I just started to work with the SQLite
I created a SQLite file (db) and I created a function that put some data in the table:
public String FirstInsert()
{
String meassage = new String();
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(COL_2,"hi how are you?");
cv.put(COL_3,"blabla");
cv.put(COL_4,"blabla");
cv.put(COL_5,"blabla");
cv.put(COL_6,"blabla");
cv.put(COL_7,"blabla");
cv.put(COL_8,"blabla");
cv.put(COL_9,"blabla");
cv.put(COL_10,"blabla");
cv.put(COL_11,"blabla");
long result = db.insert(TABLE_NAME,null,cv);
if(result == -1)
{
meassage = new String("Bad");
}
else
{
meassage = new String("Good");
}
return meassage;
}
I want the do more spesific select that take only one item, the COL_2 and the row is number that I get so I wrote this code:
public Cursor GetQuestions(int num)
{
//num++;
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("SELECT QUESTION FROM " + TABLE_NAME + "ORDER BY " + num + "ASC LIMIT 1",null);
return res;
}
this is the right code? and if it is why I got an error here too?
Thank you very much for trying to help!
yes,that's because not having space between words of sqlite code
and it's better to close your cursor and your db after every query
like this
res.close();
db.close();
I just saw that i had to do space in the SQLite code like this:
Cursor res = db.rawQuery("SELECT QUESTION FROM " + TABLE_NAME + "**&**ORDER BY " + num + "**&**ASC LIMIT 1",null);
& = space (I write & to show where I added the spaces.
I have created a SpinnerActivity, which looks like following:
http://img4.fotos-hochladen.net/uploads/bildschirmfotovse8j4po1t.png
Now for example if I select 'Landschaft' (in English: landscape) I want to search in the DatabaseHandler.java for a location which is in the category 'Landschaft' (landscape)
Therefore I have written the following method in DatabaseHandler.java:
In this method, I have just written Kategorie = Landscape.
However I want, that the selected SpinnerArray (Landschaft, Brücken...etc.) in my Spinner would be inserted in my DatabaseHandler instead of "Landschaft", how can I do that?
public List<Position> getAllPositionsWithCategory() {
List<Position> positionList = new ArrayList<Position>();
String selectQuery = "SELECT * FROM " + TABLE_POSITIONS
+ " WHERE Kategorie = 'Landschaft'";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Position position = new Position();
position.setID(Integer.parseInt(cursor.getString(0)));
position.setName(cursor.getString(1));
position.setKategorie(cursor.getString(2));
position.setLaenge(cursor.getFloat(3));
position.setBreite(cursor.getFloat(4));
// Adding position to list
positionList.add(position);
} while (cursor.moveToNext());
}
}
Simply replace the the fixed String with ? in your query, and pass the value to be inserted in the second argument of db.rawQuery().
The following might work for your case:
String selectQuery = "SELECT * FROM " + TABLE_POSITIONS
+ " WHERE Kategorie = ?";
// ...
Cursor cursor = db.rawQuery(selectQuery, new String[] { "Landschaft" });
You can now replace your String "Landschaft" with a variable of your choice.
See also: http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#rawQuery(java.lang.String,%20java.lang.String[])
I currently I have my database set up like the following:
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_ROWID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_LOCKERNUMBER
+ " TEXT NOT NULL, " + KEY_STATUS + " INTEGER, " + KEY_PIN
+ " INTEGER);");
And I am trying to write a method to get the pin code from the column for a specific locker number. Any ideas? I am very new I would like think I would need to use the query function and a cursor. I just one to get the integer value and store it into an int variable so I can compare the pin codes from what the user types in to the one in the database.
Queries to database returns in a Cursor object. You should use the db.query() method to get a row(s). Pass the table name, an array of columns you want to get (or null if you want all of them), pass a selection string that should be like "id = ?" or "key > ?", etc, then pass a String array containing the value for those ? inside the previous string,
and finally pass null for having, groupBy and orderBy unless you want to use them.
Cursor cursor = db.query(TABLE_NAME, new String[] { KEY_ROWID }, "id = ?", new String[] { Integer.toString(id) }, null, null, null);
After you get the Cursor, do cursor.moveToFirst() or cursor.moveToPosition(0) (can't remember the exact method, but the point is to move the cursor to the first retrieved row)
then you're going to iterate through the cursor with
while(cursor.moveToNext()) {
int keyRowIdColumnIndex = cursor.getColumnIndex(KEY_ROWID);
int yourValue = cursor.getInt(keyRowIdColumnIndex);
int keyLockNumberColumnIndex = cursor.getColumnIndex(KEY_LOCKNUMBER);
int pin = cursor.getInt(keyLockNumberColumnIndex);
}
This is a pretty straight forward task and there is a bunch of tutorials, examples, similar questions on SO:
How to perform an SQLite query within an Android application?
In general - you need to query the database passing your search arguments. See the documentation.
It will return you a Cursor with the matching results, which you can then iterate over and manipulate as you wish.
Fyi - storing password in a database table is a bad idea. On Android databases can be accessed and easily read. You either need to encrypt your data or think of another way to store it if it's important.
//Try This code
public String getLabeId(String LockNo)
{
ArrayList<String> Key_Pin_array = new ArrayList<String>();
Cursor cur = db.rawQuery("SELECT * FROM DATABASE_TABLE where KEY_LOCKERNUMBER = '" + LockNo + "'", null);
try {
while (cur.moveToNext())
{
System.out.println("Key_Pin" + cur.getString(3));
Key_Pin_array.add(cur.getString(3));
}
}
catch (Exception e)
{
System.out.println("error in getLabelID in DB() :" + e);
}
finally
{
cur.close();
}
return id;
}