Android.database.cursorindexoutofboundsexception: index 0 requested, with a size of 0

Question

Problem :

I am trying to use the custom adapter extending cursor adapter for displaying data in the listview, So that I can display particular phone number that I have passed the id to a method in the database class however it is giving following error :

errorandroid.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 

while I was trying to place the debugger in the method it is not going after the below line

mynum = mycursor.getString(mycursor.getColumnIndex("ContactNumber"));

Below is my code:

public String getNumberFromId(int my id) 

{

    String mynum;

    mydb= this.getReadableDatabase();

    Cursor mycursor = mydb.query(scheduletable, new String[] { "ContactNumber" },"_id="+myid, null, null, null, null);

    mycursor.moveToFirst();

    mynum = mycursor.getString(mycursor.getColumnIndex("ContactNumber")); 

    mycursor.close();

    mydb.close();

    return mynum;

}

 

Can someone help me to resolve my issue?

Answer 1

Please make sure whenever you want to deal with the Cursors, to have the check for null and also check for moveToFirst() without fail as shown below :

if( mycursor != null && mycursor.moveToFirst() ){

mynum = mycursor.getString(mycursor.getColumnIndex("ContactNumber"));

mycursor.close(); 

}

Place your logs appropriately to see that whether it is returning null or an empty cursor. According to the output modify your query.

Please have both the checks in a single statement as mentioned in the example above.

Also always put the close() call within the valid cursor scope.