Consider the following code snippet to query SQLite database: String[] result_columns = new String[] {KEY_ID, COL1, COL2}; Cursor allRows = myDatabase.query(true, DATABASE_TABLE, result_columns, null, null, null, null, null, null); Which of the following prints out the values of COL1 column correctly if the result is not empty? A) if (allRows.moveToFirst()) { do { System.out.println(allRows.getString(1)); } While (allRows.moveToNext()); } B) do { System.out.println(allRows.getString(0)); while (allRows.moveToNext()); C) /system/app//files D) if (allRows!= null) { while (!allRows.isNull()); }

Question

Consider the following code snippet to query SQLite database: String[] result_columns = new String[] {KEY_ID, COL1, COL2}; Cursor allRows = myDatabase.query(true, DATABASE_TABLE, result_columns, null, null, null, null, null, null); Which of the following prints out the values of COL1 column correctly if the result is not empty?
A) if (allRows.moveToFirst()) {              do {             
System.out.println(allRows.getString(1));             
}
While (allRows.moveToNext()); }
B) do {              System.out.println(allRows.getString(0)); while (allRows.moveToNext());
C) /system/app/<package name>/files
D) if (allRows!= null) { while (!allRows.isNull()); }

Quizplus · Accepted Answer

Option A is the correct choice as it uses the moveToFirst() method to move the cursor to the first row and getString(1) to retrieve the value of COL1 column. Then, it uses the moveToNext() method to move the cursor to the next row until there are no more rows in the cursor. This will print out the values of COL1 column correctly if the result is not empty. 
Option B and D are incorrect as they do not use the correct methods to retrieve the data from the cursor. 
Option C is irrelevant to the question.

Consider the Following Code Snippet to Query SQLite Database: String[]