Pretty sure this is an easy one, but i'm getting confused by all the examples that adapt the data returned from a cursor into different views. I just want to run a rawquery and put each item of data returned into a float array (so that i can add them up later). What do i need to use for this? Thanks
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1Have you forgotten to initialize the budgetInArray (presumably you want to do that just after the "numRows = incomeCursor.getCount()" line)?Jon Colverson– Jon Colverson2011-01-30 15:28:31 +00:00Commented Jan 30, 2011 at 15:28
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Yes that was exactly the problem, just got there myself -_- Thanks for pointing it out too :)Holly– Holly2011-01-30 15:32:32 +00:00Commented Jan 30, 2011 at 15:32
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2 Answers
You'll still have a cursor when you query your database, but once you got the cursor you could iterate over it, pulling out the values you need into an array, like this:
DbAdapter db = new DbAdapter(mContext);
int columnIndex = 3; // Whichever column your float is in.
db.open();
Cursor cursor = db.getAllMyFloats();
float[] myFloats = new float[cursor.getCount()-1];
if (cursor.moveToFirst())
{
for (int i = 0; i < cursor.getCount(); i++)
{
myFloats[i] = cursor.getFloat(columnIndex);
cursor.moveToNext();
}
}
cursor.close();
db.close();
// Do what you want with myFloats[].
3 Comments
Holly
ahhh wicked thank you very much! The only thing i don't understand is the need to use columnIndex? I suppose i'll find out if i look into the method. I assume the actual rawQuery is done in getAllMyFloats right? Cheers this really helped.
Holly
oh also one other thing, do the columns start at an index of 0 or 1?
John J Smith
If you have a table with several columns, then you'll need the column index to get the specific data field you're looking for. Columns are zero-indexed.
Don't minus by 1 in float[] myFloats = new float[cursor.getCount()-1]; because (int i =0) or i start from 0. If you use it, will appear Java.lang.IndexOutOfBoundsException. You need array index until [cursor.getCount()], not until [cursor.getCount()-1]. So the correct thing is float[] myFloats = new float[cursor.getCount()];
