How do i get data from an SQLITE database to an array in android?
Pretty sure this开发者_StackOverflow社区 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
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[].
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()];
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