Android SQLite query cursor moveToFirst - android

I'm making an Android App with a sqlite db, which has a query method like this:
String[] projection = {COLUMN_NAME_ID};
String selection = COLUMN_NAME_TEAM + " = ?";
String[] selectionArgs = {teamId.toString()};
String sortOrder = COLUMN_NAME_NAME + " ASC";
Cursor c = db.query(TABLE_NAME, projection, selection, selectionArgs, null, null, sortOrder);
if (c.moveToFirst()){
//...
}
as suggested here. The point is to implement this query:
SELECT PLAYER_ID FROM PLAYERS WHERE TEAM_ID = ? ORDER BY NAME ASC;
According to the SQLiteDatabase.query documentation, this is a valid call to query(), and so far I've been doing it successfully with all my other queries in this App.
For some reason, in this query (and only in this) the App freezes in c.moveToFirst().
Some answers to similar questions suggest that it might be a performance issue. I don't think this is the case, as my table has only 6 rows and the query is quite simple.
Any ideas?
Thanks

Related

How to do a rtrim() to a Android Cursor query?

I have the following query:
Cursor c = sd.query(itemsTable.Table_Name, columns, itemsTable.ItemNumber + "= ?", selectionArgs, null, null, null);
I need to be able to do this:
'SQL Query I am running on the database using for testing
select * from items where rtrim(itemnumber) = '292664'
Where itemnumber is my selectionArgs.
The SQL query returns the correct results but the cursor query returns null.
I would rather not change the way I am running queries and would like to know if there is a way to convert my existing query to work the same as the SQL query.
Try the following:
String selection = "RTRIM(" + itemsTable.ItemNumber + ") = ?";
String[] selectionArgs = new String[] {"292664"}; // or whatever
Cursor c = sd.query(itemsTable.Table_Name, columns, selection, selectionArgs, null, null, null);

SQLiteDatabase Cursor empty only on Android 5.0+ devices

The application has a SearchView which fetches suggestions from a specific database table. Everything worked without any errors until Android 5.0 appeared.
As of then, when the SQLiteQueryBuilder queries the database to fill the Cursor object, the return is empty cursor. Not NULL, but empty.
On other platforms, I can output the Cursor's content via DatabaseUtils.dumpCursorToString(cursorObject), but on Android 5.0+ the method reports output on null objects
Dumping cursor null
<<<<<
Even more: when I extract database file from 5.0+ devices and run the local SQL query, I can fetch all data. So the database is valid indeed. And the query is the simplest one
SELECT rowid AS _id, suggest_text_1, suggest_text_2, rowid AS suggest_intent_data_id
FROM fts
WHERE (fts MATCH '*e*') //<-- I pressed "e" on the keyboard
The logic for selecting data from the database and filling the Cursor object is really simple
SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
builder.setTables(FTS3_TABLE);
builder.setProjectionMap(mColumnMap);
Cursor cursor = builder.query(db,columns, selection, selectionArgs,
null, null, null);
I tried looking for some deprecated methods, but was without any luck.
I have already spent 3 days debugging each step in the process and I am out of any ideas what could be causing such behaviour.
Anyone has any ideas?
EDIT
The output of the method buildQuery()
String query = builder.buildQuery(columns, selection, null, null, null, null);
RESULT:
SELECT rowid AS _id, suggest_text_1, suggest_text_2, rowid AS suggest_intent_data_id
FROM fts
WHERE (fts MATCH ?)
selection and selectionArgs parameters are created like this
String selection = FTS3_TABLE + " MATCH ?";
String[] selectionArgs = new String[]{"*" + query + "*"};
The RAW query resulted the same thing as query via builder.query()
String query = builder.buildQuery(columns, selection, null, null, null, null);
Cursor temp = db.rawQuery(query, selectionArgs);
String output = DatabaseUtils.dumpCursorToString(temp);
Output: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor#295023a7
<<<<<
Answered https://stackoverflow.com/a/30710226/437039 by laalto
MATCH '*foo*' queries never worked correctly in any version of sqlite. The fact that you got some results earlier was just a coincidence. Just the prefix form MATCH 'foo*' (and MATCH 'foo') are supported.
Lollipop ships with a newer version of sqlite. For detailed list of changes between sqlite versions, see the changelog.
Have you tried to query using the SQLiteDatabase query method like the following?
String selection = "fts" + " =? AND " +
String[] selectionArgs = new String [] {
"*e*"
};
String[] projection = new String [] { "rowId", "suggested_text"};
SQLiteDatabase db = mDbHelper.getReadableDatabase();
Cursor cursor = db.query("tableName",
projection,selection, selectionArgs, null, null, null);

How to use selection args to query specific rows from a contentprovider in android

i have constructed a basic content provider that stores SMS messages for learning purposes, so far i can read(without selection args), insert, update and delete.
However i have been stumped trying to figure out how to format the selection args for the WHERE clause in my provider:
Basicly my application needs to search for a specific timestamp (in long format) and return its _id
say your database has an entry like this that your trying to access:
2|1|1410293471300|test type 1||testing|0
and the entire database looks like this:
_id|CLIENTTRXID|CREATED_AT|TYPE|MESSAGEPRIO|MESSAGE|ACCEPTED
1|1|1410293471000|test type 1||testing|0
2|1|1410293471300|test type 1||testing|0
3|1|1410293471600|test type 1||testing|0
in sql the query would be
"select _id from alerts where CREATED_AT=1410293471300;"
the code i was hoping would do the equivalent:
//normally i would get the string dynamically but to make it equal to the sql
String date = "1410293471300";
String[] selectionArgs = new String[]{ date };
Cursor cursor = getContext().getContentResolver().query(AlertContract.CONTENT_URI, null, AlertContract.Column.CREATED_AT, selectionArgs, AlertContract.DEFAULT_SORT);
seems to always produce the following error no matter what i try as selectionArgs
Exception caught﹕ Cannot bind argument at index 1 because the index is out of range. The statement has 0 parameters.
here is the query method of my contentprovider:
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables( AlertContract.TABLE);
switch (sURIMatcher.match(uri)) {
case AlertContract.STATUS_DIR:
break;
case AlertContract.STATUS_ITEM:
qb.appendWhere(AlertContract.Column.ID + "=" + uri.getLastPathSegment());
break;
default:
throw new IllegalArgumentException( "illegal uri: " + uri);
}
String orderBy = (TextUtils.isEmpty(sortOrder)) ? AlertContract.DEFAULT_SORT : sortOrder;
SQLiteDatabase db = dbHelper.getReadableDatabase();
Cursor cursor = qb.query(db, projection, selection, selectionArgs, null, null, orderBy);
//register for uri changes
cursor.setNotificationUri(getContext().getContentResolver(), uri);
Log.d(TAG, "queried records: "+cursor.getCount());
return cursor;
}
Presumably im missing something extremely obvious, and will feel quite silly for having posted this question.
But for the moment i would very much appreciate any help, as i am quite stumped.
It looks like your issue is with your selection, rather than with your selectionArgs per se. The selection should be the whole query after the "where". Here your selection is "CREATED_AT". You need two more items to get it to work:
an =, since you want equality (you can also do other operators, of course)
a ?. This is where your selectionArgument will be inserted (each argument needs a ? in the selection, so there should be the same number of ?s in the selection as selectionArguments.
The end result should be more like "CREATED_AT = ?"
Check out the documentation and this tutorial for more info on how to correctly construct a ContentProvider query.
When you query the content provider, try the following. The selection should be AlertContract.Column.CREATED_AT + "=?"
Cursor cursor = getContext().getContentResolver().query(AlertContract.CONTENT_URI, null, AlertContract.Column.CREATED_AT + "=?", selectionArgs, AlertContract.DEFAULT_SORT);

ContactsContract.Data implicit-join columns not working?

Sorry if this might be a duplicate question, I've spent the evening trying to wrap my head around this, and I can't seem to find other posts that might cast some light on this as well, so I am hoping that a few more pair of eyes might spot something.
I am having this impression from the API docs for ContactsContract.Data that when you specify certain fields, the library does some magic and performs an implicit join for you in the background.
Doesn't seem to be working for me.
import android.provider.ContactsContract.CommonDataKinds.Phone;
private Cursor getContacts()
{
// Run query
Uri uri = Phone.CONTENT_URI;
String[] projection = new String[] {
Phone.DISPLAY_NAME,
Phone.NUMBER,
Phone.CONTENT_ITEM_TYPE,
Phone.HAS_PHONE_NUMBER,
Phone.IN_VISIBLE_GROUP
};
String selection = Phone.HAS_PHONE_NUMBER + " = '1' AND " + Phone.IN_VISIBLE_GROUP + " = '1'";
String[] selectionArgs = null;
String sortOrder = Phone.DISPLAY_NAME + " COLLATE LOCALIZED ASC";
return getContentResolver().query(uri, projection, selection, selectionArgs, sortOrder);
}
When this is run, it dies with a:
java.lang.IllegalArgumentException: Invalid column vnd.android.cursor.item/phone_v2
From the docs for ContactsContract.CommonDataKinds.Phone it clearly states that:
You can use all columns defined for ContactsContract.Data as well as the following aliases.
What am I missing?
Phone.CONTENT_ITEM_TYPE is your problem. That's not a column name, that's a constant that Data.MIME_TYPE is set to. Remove it from your projection and it should be fine.

Group By in ContentResolver in Ice Cream Sandwich

I am making a query on the Android Contacts ContentProvider. I need a Group By clause. In Gingerbread and Honeycomb, I do something like this to search phone numbers and emails at the same time:
(The actual WHERE clause is much more complicated as it includes types checks. This is a simplification, but it yields the same result)
String request = Phone.NUMBER + " LIKE ? OR " + Email.DATA + " LIKE ?";
String[] params = new String["%test%", "%test%"];
Cursor cursor = getContentResolver().query(
Data.CONTENT_URI,
new String[] { Data._ID, Data.RAW_CONTACT_ID },
request + ") GROUP BY (" + Data.RAW_CONTACT_ID,
params, "lower(" + Data.DISPLAY_NAME + ") ASC");
The injection of the ')' finishes the WHERE clause and allow the insertion of a GROUP BY clause.
However, in Ice Cream Sandwich, it appears that the ContentProvider detects this and adds the correct number of parenthesis to prevent my injection. Any other way of doing this in a single cursor query?
Edit
Currently, I have removed the GROUP BY, and added a MatrixCursor to limit the impact, but I'd rather have a real cursor:
MatrixCursor result = new MatrixCursor(new String[] { Data._ID, Data.RAW_CONTACT_ID });
Set<Long> seen = new HashSet<Long>();
while (cursor.moveToNext()) {
long raw = cursor.getLong(1);
if (!seen.contains(raw)) {
seen.add(raw);
result.addRow(new Object[] {cursor.getLong(0), raw});
}
}
I recently battled this issue querying the CallLog.Calls DB (where we were not able to modify the ContentProvider). What we ended up going with was building a query that looked like this:
SELECT _id, date, duration, type, normalized_number FROM calls WHERE _id IN (
SELECT _id FROM calls WHERE date < ? GROUP BY normalized_number ORDER BY date DESC LIMIT ?
);
The idea here is that we place any valid sqlite in our subquery, return a list of ids and then query again for all calls with those ids.
The final code looked something like this:
String whereClause = "_id IN (SELECT _id FROM calls WHERE data < ? GROUP BY normalized_number ORDER BY date DESC LIMIT ?)";
Cursor cursor = context.getContentResolver().query(
CallLog.Calls.CONTENT_URI,
new String[] { "_id", "date", "duration", "normalized_number" },
whereClause,
new String[]{ String.valueOf(amount), String.valueOf(dateFrom) },
null
);
...
In the case that you're querying for contacts, it would look something like this:
String whereClause = "_id IN (SELECT _id FROM contacts WHERE " + Phone.NUMBER + " LIKE ? OR " + Email.DATA + " LIKE ? GROUP BY " + Data.RAW_CONTACT_ID + " ORDER BY lower(" + Data.DISPLAY_NAME + ") ASC)";
String[] params = new String["%test%", "%test%"];
Cursor cursor = getContentResolver().query(
Data.CONTENT_URI,
new String[] { Data._ID, Data.RAW_CONTACT_ID },
whereClause,
params,
null
);
There will be some decrease in performance (since we're essentially querying twice for the same results), but it will surely be a lot faster than querying for all calls and doing the GROUP BY work in java world and also allows you to build up the query with additional clauses.
Hope this helps. We used this on Oreo and it fulfilled our needs.
You could create a custom Uri such that when your UriMatcher in your ContentProvider gets it, you can insert your group by clause and then execute the raw sql directly on the database.
first off all excuse my POOR English!
I'm new to Java/Android, started with 4.2.1 and fight with that too almost 2 days, then i start reading some more details about SQLiteQueryBuilder the query part is pretty much that what u are looking for ;)
it have:
public Cursor query (SQLiteDatabase db, String[] projectionIn, String selection, String[] selectionArgs, String groupBy, String having, String sortOrder)
the query "function" of the Content Provider only gives you:
query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder)
here u can trick around, i will post you my code snip:
#Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
final SQLiteDatabase db = mOpenHelper.getReadableDatabase();
/* a String is a Object, so it can be null!*/
String groupBy = null;
String having = null;
switch (sUriMatcher.match(uri)) {
...
...
...
case EPISODES_NEXT:
groupBy = "ShowID";
queryBuilder.setTables(EpisodenTable.TableName);
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
Cursor c = queryBuilder.query(db, projection, selection, selectionArgs,
groupBy, having, sortOrder);
c.setNotificationUri(getContext().getContentResolver(), uri);
return c;
}
thats its!
here the code i use to execute:
Cursor showsc = getContext().getContentResolver().query(
WhatsOnTVProvider.CONTENT_EPISODES_NEXT_URI,
EpisodenTable.allColums_inclCount,
String.valueOf(Calendar.getInstance().getTimeInMillis() / 1000)
+ " < date", null, null);

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