The order of calling ContentResolver.query() make a difference results

I am working on an android app. there is a table that has the following schema

question_link String
answer_link String
field_link String

I am working with the database with content provider

if the data for the table (for each row: question_link then answer_link then field_link) is:

• car ___ bus ___auto
• truck ___bike ___auto
• car ___bike ___auto

when I run the following code:

Cursor cursor1 = contentResolver.query(uri,
                    new String[]{question_link},
                    question_link + " = ? " ,
                    new String[]{"car"},
                    null);
int c1 = cursor1.getCount(); // the c1 becomes 2
Cursor cursor2 = contentResolver.query(uri,
                    new String[]{answer_link},
                    answer_link + " = ? " ,
                    new String[]{"bike"},
                    null);
int c2 = cursor2.getCount(); // the c2 becomes 1

There is 2 "car" in the question_link column and there is 2 "bike" in the answer_link column. why cursor1 its count is 2 and cursor2 its count is 1? if I run the following code which I query answer_link first:

Cursor cursor1 = contentResolver.query(uri,
                        new String[]{answer_link},
                        answer_link + " = ? " ,
                        new String[]{"bike"},
                        null);
    int c1 = cursor1.getCount(); // the c1 becomes 2
Cursor cursor2 = contentResolver.query(uri,
                        new String[]{question_link},
                        question_link + " = ? " ,
                        new String[]{"car"},
                        null);
    int c2 = cursor2.getCount(); // the c2 becomes 1

The data is a same, how the order make a difference? I do not understand. what is the problem? and how can I solve it?