I have been stuck at one point from long time, i.e with the use of
SimpleCursorAdapter
as it fails while returning the correct value. I have seen similar many post in SO itself, saying that I should add _id column in the cursor database query, rather I should do
db.rawQuery(String,String)
My code in the onCreate(..) is
HospitalData = new Database(this);
HospitalData.open();
Cursor c = HospitalData.getAllRows_Patient_Db();
startManagingCursor(c);
c.moveToFirst();
//HERE SOME LOOP IS NEEDED FOR TRAVERSING AND PUTTING IN THE LISTVIEW
while(c.isAfterLast() == false)
{
String[] columns = new String[] { c.getString(1), c.getString(2) };
int[] to = new int[] { R.id.room_number_db, R.id.pt_initial_db };
adapter = new SimpleCursorAdapter(this,R.layout.patient_db, c,columns,to);
c.moveToNext();
}
setListAdapter(adapter);
And previously my database accessing code was as follows
public Cursor getAllRows_Patient_Db()
{
return db.query(DATABASE_PATIENT_TABLE, new String[] {KEY_ROWID, KEY_ROOM_NUMBER,
KEY_PATIENT_INITIAL
},
null,
null,
null,
null,
null);
}
where KEY_ROWID is defined as follows
public static final String KEY_ROWID = "_id";
And the error with this is
07-04 22:10:23.301: ERROR/AndroidRuntime(16795): Caused by: java.lang.IllegalArgumentException: column '90' does not exist
07-04 22:10:23.301: ERROR/AndroidRuntime(16795): at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:314)
07-04 22:10:23.301: ERROR/AndroidRuntime(16795): at android.widget.SimpleCursorAdapter.findColumns(SimpleCursorAdapter.java:312)
Here column 90 is not the column id but according to my database is the data stored in cursor.getString(1), but I think here it is trying to search cursor.getString(0) which is the row id.
Later I changed my code as follows
public Cursor getAllRows_Patient_Db()
{
String db_sel = "SELECT id as _id, KEY_ROOM_NUMBER" +
",KEY_PATIENT_INITIAL FROM DATABASE_PATIENT_TABLE";
return db.rawQuery(db_sel,null);
}
But still I am getting error, this time error is different
07-04 21:36:12.510: ERROR/global(9861): Deprecated Thread methods are not supported.
07-04 21:36:12.950: ERROR/AndroidRuntime(9861): FATAL EXCEPTION: main
07-04 21:36:12.950: ERROR/AndroidRuntime(9861): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pro/com.pro.CopyOfFirstScreen}: android.database.sqlite.SQLiteException: no such table: DATABASE_PATIENT_TABLE: , while compiling: SELECT id as _id, KEY_ROOM_NUMBER,KEY_PATIENT_INITIAL FROM DATABASE_PATIENT_TABLE
07-04 21:36:12.950: ERROR/AndroidRuntime(9861): Caused by: android.database.sqlite.SQLiteException: no such table: DATABASE_PATIENT_TABLE: , while compiling: SELECT id as _id, KEY_ROOM_NUMBER,KEY_PATIENT_INITIAL FROM DATABASE_PATIENT_TABLE
I am stuck with it from very long time, please help!!
EDIT : Okay now with you guys help my query statement is correct and thanks for that, I am sorry I am not good in understanding the syntax for database query but I am trying to learn
The working query after changes is
String db_sel = "SELECT _id as _id, room_number" +",patient_initial FROM " + DATABASE_PATIENT_TABLE;
Actually I had to change the declared String with the key values
public static final String KEY_ROWID = "_id";
public static final String KEY_ROOM_NUMBER = "room_number";
public static final String KEY_PATIENT_INITIAL = "patient_initial";
But now I see another problem that is not from the query statement but the way I am accessing or using the simplecursorAdapter
As you can see that my table has 2 rows and 3 columns, Now I want to fetch the data from column 2 and column 3 and put it in my listview.
But after the fix from the query I am getting another error
Originally it was
String[] columns = new String[] {c.getString(1), c.getString(2) };
int[] to = new int[] { R.id.room_number_db, R.id.pt_initial_db };
adapter = new SimpleCursorAdapter(this,R.layout.patient_db, c,columns,to);
c.moveToNext();
setListAdapter(adapter);
And the error was
07-05 21:32:29.228: ERROR/AndroidRuntime(1505): Caused by: java.lang.IllegalArgumentException: column '90' does not exist
07-05 21:32:29.228: ERROR/AndroidRuntime(1505): at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:314)
07-05 21:32:29.228: ERROR/AndroidRuntime(1505): at android.widget.SimpleCursorAdapter.findColumns(SimpleCursorAdapter.java:312)
android.widget.SimpleCursorAdapter.findColumns(SimpleCursorAdapter.java:312)
As you can see it is trying to access the data of first column inspite of accessing the row
After that I made changes in my code
int x = 0;
String[] columns = new String[] { c.getString(0),c.getString(1), c.getString(2) };
int[] to = new int[] { x, R.id.room_number_db, R.id.pt_initial_db };
adapter = new SimpleCursorAdapter(this,R.layout.patient_db, c,columns,to);
c.moveToNext();
setListAdapter(adapter);
This was only a guess in order to find out how differently SimpleCursorAdapter works compared to a normal cursor and the error I get is
07-05 21:34:47.947: ERROR/AndroidRuntime(1966): Caused by: java.lang.IllegalArgumentException: column '1' does not exist
07-05 21:34:47.947: ERROR/AndroidRuntime(1966): at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:314)
I know this question is becoming too long 🙁 do u suggest me to remove some code from here.
The problem is fixed, the main thing is that I should make sure I always query for the _id with each query to the database, but if I do it with cursor.getString(someIndex) then this gets misleaded as the adapter in my case is taking the content of first column as the rowid and is trying to search the row.
Nether doing rawQuery(),or using “Select _id as _id” stuffs are mandatory. these things are sometime misleading as I felt.
So keeping things simple below is the code.
Database code
Activity Code