why sqlite insertion detects conflict when the relation is one to many?

I want to add some rows in comment table to the same id in phone table.

however it seems my query allows only one row per phone_id.

how can I fix this?

That's strange as I didn't declare a primary key or unique key in the comment table

So the relation phone-comment should be one to many.

public class CommentDal extends SQLiteOpenHelper {

    // Database Version
    private static final int DATABASE_VERSION = 1;
    // Database Name
    private static final String DATABASE_NAME = Constants.DB_NAME;

    private static final String COMMENTS_TABLE = "COMMENTS_TABLE";

    public CommentDal(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // SQL statement to create book table

        String CREATE_COMMENTS_TABLE =
                "CREATE TABLE " + COMMENTS_TABLE +
                        " ( "+ KEY_ID+" INTEGER, "
                             + KEY_COMMENT_TEXT+" TEXT, "
                             + "FOREIGN KEY("+KEY_ID+") REFERENCES "+PhoneDal.BLOCKED_PHONES_TABLE+"("+KEY_ID+"))";

        db.execSQL(CREATE_COMMENTS_TABLE);

    }


    private static final String KEY_ID = "id";
    private static final String KEY_COMMENT_TEXT = "KEY_COMMENT_TEXT";

    public void addItem(long phoneID, String comment) {
        Log.d(Constants.LOGGER_TAG, "add saved-offer");
        // 1. get reference to writable DB
        SQLiteDatabase db = this.getWritableDatabase();

        // 2. create ContentValues to add key "column"/value
        ContentValues values = new ContentValues();
        values.put(KEY_ID, phoneID);
        values.put(KEY_COMMENT_TEXT, comment);

        // 3. insert
        long newRowId = db.insertWithOnConflict(COMMENTS_TABLE, null, values,
                SQLiteDatabase.CONFLICT_REPLACE);
        // 4. close
        db.close();