Вы можете использовать один тип столбца (INTEGER), т. Е. Хранить и извлекать как Java long (your_cursor.getLong()).
Тогда вы можете иметь до 64 флажков (1 на бит).
Ниже показано, как вы можете манипулировать флажками из данных, хранящихся в столбце, исходя из того, что первый равен 0последний - 63 (т. е. для установки флажка или проверки флажка).
Операция использовалась для проверки и дала некоторые результаты.
: -
public class CheckList extends AppCompatActivity {
// The value stored in a column (rightmost bit represents first checkbox, ... leftmost bit represents 64th checkbox)
long db_value = (long) 0b11010000_00000000_00000000_00000000_01100000_00000000_00000000_00010101L;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_check_list);
db_value = setCheckBox(db_value,8); // set the 9th (offset 8)
db_value = setCheckBox(db_value,0); //already set
// Inspect and report on all 64 checkboxes
for (int i=0;i < 64; i++) {
Log.d(
"CHECKBOX CHECKED",
"Checked Offset " + String.valueOf(i) +
" checked value is " + String.valueOf(
isCheckBoxNChecked(db_value,i)
)
);
}
}
/**
* test to see if checkbox n (0-63) is set
* @param value_from_db_column the value extracted from the db that represents all checkboxes
* @param checkbox_to_check the checkbox to be tested
* @return true if checked else false
*/
public boolean isCheckBoxNChecked(long value_from_db_column, int checkbox_to_check) {
return BigInteger.valueOf(value_from_db_column).testBit(checkbox_to_check);
}
/**
* Set checkbox n (0-63)
* @param current_checkbox the current checkbox status
* @param checkbox_to_set the checkbox to be set
* @return the amended checkbox status
*/
public long setCheckBox(long current_checkbox, int checkbox_to_set) {
return BigInteger.valueOf(current_checkbox).setBit(checkbox_to_set).longValue();
}
}
Результат
D/CHECKBOX CHECKED: Checked Offset 0 checked value is true
D/CHECKBOX CHECKED: Checked Offset 1 checked value is false
D/CHECKBOX CHECKED: Checked Offset 2 checked value is true
D/CHECKBOX CHECKED: Checked Offset 3 checked value is false
D/CHECKBOX CHECKED: Checked Offset 4 checked value is true
D/CHECKBOX CHECKED: Checked Offset 5 checked value is false
D/CHECKBOX CHECKED: Checked Offset 6 checked value is false
D/CHECKBOX CHECKED: Checked Offset 7 checked value is false
D/CHECKBOX CHECKED: Checked Offset 8 checked value is true
D/CHECKBOX CHECKED: Checked Offset 9 checked value is false
D/CHECKBOX CHECKED: Checked Offset 10 checked value is false
D/CHECKBOX CHECKED: Checked Offset 11 checked value is false
D/CHECKBOX CHECKED: Checked Offset 12 checked value is false
D/CHECKBOX CHECKED: Checked Offset 13 checked value is false
D/CHECKBOX CHECKED: Checked Offset 14 checked value is false
D/CHECKBOX CHECKED: Checked Offset 15 checked value is false
D/CHECKBOX CHECKED: Checked Offset 16 checked value is false
D/CHECKBOX CHECKED: Checked Offset 17 checked value is false
D/CHECKBOX CHECKED: Checked Offset 18 checked value is false
D/CHECKBOX CHECKED: Checked Offset 19 checked value is false
D/CHECKBOX CHECKED: Checked Offset 20 checked value is false
D/CHECKBOX CHECKED: Checked Offset 21 checked value is false
D/CHECKBOX CHECKED: Checked Offset 22 checked value is false
D/CHECKBOX CHECKED: Checked Offset 23 checked value is false
D/CHECKBOX CHECKED: Checked Offset 24 checked value is false
D/CHECKBOX CHECKED: Checked Offset 25 checked value is false
D/CHECKBOX CHECKED: Checked Offset 26 checked value is false
D/CHECKBOX CHECKED: Checked Offset 27 checked value is false
D/CHECKBOX CHECKED: Checked Offset 28 checked value is false
D/CHECKBOX CHECKED: Checked Offset 29 checked value is true
D/CHECKBOX CHECKED: Checked Offset 30 checked value is true
D/CHECKBOX CHECKED: Checked Offset 31 checked value is false
D/CHECKBOX CHECKED: Checked Offset 32 checked value is false
D/CHECKBOX CHECKED: Checked Offset 33 checked value is false
D/CHECKBOX CHECKED: Checked Offset 34 checked value is false
D/CHECKBOX CHECKED: Checked Offset 35 checked value is false
D/CHECKBOX CHECKED: Checked Offset 36 checked value is false
D/CHECKBOX CHECKED: Checked Offset 37 checked value is false
D/CHECKBOX CHECKED: Checked Offset 38 checked value is false
D/CHECKBOX CHECKED: Checked Offset 39 checked value is false
D/CHECKBOX CHECKED: Checked Offset 40 checked value is false
D/CHECKBOX CHECKED: Checked Offset 41 checked value is false
D/CHECKBOX CHECKED: Checked Offset 42 checked value is false
D/CHECKBOX CHECKED: Checked Offset 43 checked value is false
D/CHECKBOX CHECKED: Checked Offset 44 checked value is false
D/CHECKBOX CHECKED: Checked Offset 45 checked value is false
D/CHECKBOX CHECKED: Checked Offset 46 checked value is false
D/CHECKBOX CHECKED: Checked Offset 47 checked value is false
D/CHECKBOX CHECKED: Checked Offset 48 checked value is false
D/CHECKBOX CHECKED: Checked Offset 49 checked value is false
D/CHECKBOX CHECKED: Checked Offset 50 checked value is false
D/CHECKBOX CHECKED: Checked Offset 51 checked value is false
D/CHECKBOX CHECKED: Checked Offset 52 checked value is false
D/CHECKBOX CHECKED: Checked Offset 53 checked value is false
D/CHECKBOX CHECKED: Checked Offset 54 checked value is false
D/CHECKBOX CHECKED: Checked Offset 55 checked value is false
D/CHECKBOX CHECKED: Checked Offset 56 checked value is false
D/CHECKBOX CHECKED: Checked Offset 57 checked value is false
D/CHECKBOX CHECKED: Checked Offset 58 checked value is false
D/CHECKBOX CHECKED: Checked Offset 59 checked value is false
D/CHECKBOX CHECKED: Checked Offset 60 checked value is true
D/CHECKBOX CHECKED: Checked Offset 61 checked value is false
D/CHECKBOX CHECKED: Checked Offset 62 checked value is true
D/CHECKBOX CHECKED: Checked Offset 63 checked value is true
Примеры SQL
Ниже описано, как можно использовать SQL для выполнения некоторых манипуляций: -
DROP TABLE IF EXISTS mycheckboxes;
CREATE TABLE IF NOT EXISTS mycheckboxes (id INTEGER PRIMARY KEY, USER TEXT, checkbox INTEGER);
INSERT INTO mycheckboxes (user,checkbox) VALUES
('Fred', (1 << 0) + (1 << 5) + (1 << 7)),
('Fred', 0 + (1 << 3) + (1 << 5) + (1 << 8)),
('Fred', 0 + (1 << 2) + (1 << 4) + (1 << 63))
;
-- Show all
SELECT * FROM mycheckboxes;
-- Only select rows where 64th checkbox is checked
SELECT * FROM mycheckboxes WHERE checkbox & (1 << 63) <> 0;
-- Only select rows where 1st and 6th checkboxes are set
SELECT * FROM mycheckboxes WHERE checkbox & (1 << 0) <> 0 AND checkbox & (1 << 5) <> 0;
- Создает таблицу с именем mycheckboxes
- Добавляет 3 строки
- У 1-й строки установлены 1-й, 6-й и 8-й флажки
- У 2-й строки 4-й, 6-й и 9-йнабор флажков
- 3-й ряд имеет 3-й 5-й и 64-й набор флажков
Результаты: -
- все строки
Выберите строки, в которых установлен 64-й флажок (только 3-й ряд)
выберите строки, в которых установлены 1-й и 6-й флажки (только 1-й ряд)
Принцип работы Android
Следующий код представляет собой простую демонстрацию того, как вышеуказанное можно использовать в простом приложении для Android.
Приложение имеет
- две кнопки (СОХРАНИТЬ, чтобы сохранить запись, и ЛОГ.Описывать сохраненные записи с точки зрения флажков).
- 6 флажков
Похоже (после того, как некоторые флажки были установлены / отмечены): -
При добавлении нескольких записей (нажатие кнопки SAVE) выходные данные в журнале могут быть: -
1-29 02:44:52.803 3633-3633/so53521994numerouscheckboxes.so53521994numerouscheckboxes D/LOGCHECKBOX: For row 1 checkboxes value is 13
Checkbox 1 is CHECKED.
Checkbox 2 is NOT CHECKED.
Checkbox 3 is CHECKED.
Checkbox 4 is CHECKED.
Checkbox 5 is NOT CHECKED.
Checkbox 6 is NOT CHECKED.
11-29 02:44:52.803 3633-3633/so53521994numerouscheckboxes.so53521994numerouscheckboxes D/LOGCHECKBOX: For row 2 checkboxes value is 42
Checkbox 1 is NOT CHECKED.
Checkbox 2 is CHECKED.
Checkbox 3 is NOT CHECKED.
Checkbox 4 is CHECKED.
Checkbox 5 is NOT CHECKED.
Checkbox 6 is CHECKED.
- Строка 2запись добавлена с указанным выше.
Код
Помощник по базе данных DatabaseHelper.java : -
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DBNAME = "mycheckboxes.db";
public static final int DBVERSION = 1;
public static final String CHECKBOX_TABLE = "mycheckboxes";
public static final String CHECKBOX_COL_ID = BaseColumns._ID;
public static final String CHECKBOX_COL_USER = "user";
public static final String CHECKBOX_COL_CHECKBOX = "checkbox";
SQLiteDatabase mDB;
public DatabaseHelper(Context context) {
super(context, DBNAME, null, DBVERSION);
mDB = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
String crt_checkbox_table = "CREATE TABLE IF NOT EXISTS " + CHECKBOX_TABLE + "(" +
CHECKBOX_COL_ID + " INTEGER PRIMARY KEY, " +
CHECKBOX_COL_USER + " TEXT, " +
CHECKBOX_COL_CHECKBOX + " INTEGER" +
")";
db.execSQL(crt_checkbox_table);
}
@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {}
public long insertEntry(String user, long checkboxes) {
ContentValues cv = new ContentValues();
cv.put(CHECKBOX_COL_USER,user);
cv.put(CHECKBOX_COL_CHECKBOX,checkboxes);
return mDB.insert(CHECKBOX_TABLE,null,cv);
}
public void logCheckBoxStatusForUser(String user, int checkbox_count) {
String whereclause = CHECKBOX_COL_USER + "=?";
String[] whereargs = new String[]{user};
Cursor csr = mDB.query(
CHECKBOX_TABLE,
null,
whereclause,
whereargs,
null,
null,
null
);
while (csr.moveToNext()) {
long currrent_checkboxes = csr.getLong(csr.getColumnIndex(CHECKBOX_COL_CHECKBOX));
StringBuilder sb = new StringBuilder("For row ")
.append(String.valueOf(csr.getPosition() + 1))
.append(" checkboxes value is ")
.append(String.valueOf(currrent_checkboxes));
for (int i = 0; i < checkbox_count; i++) {
sb.append("\n\tCheckbox ")
.append(String.valueOf(i+1))
.append(" is ");
if (CheckList.isCheckBoxNChecked(currrent_checkboxes,i)) {
sb.append("CHECKED.");
} else {
sb.append(" NOT CHECKED.");
}
}
Log.d("LOGCHECKBOX",sb.toString());
}
}
}
Активность CheckList.java : -
public class CheckList extends AppCompatActivity {
CheckBox[] checkboxes = new CheckBox[6];
Button save,logit;
DatabaseHelper mDBHlpr;
String current_user = "Fred";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_check_list);
mDBHlpr = new DatabaseHelper(this);
checkboxes[0] = this.findViewById(R.id.cb01);
checkboxes[1] = this.findViewById(R.id.cb02);
checkboxes[2] = this.findViewById(R.id.cb03);
checkboxes[3] = this.findViewById(R.id.cb04);
checkboxes[4] = this.findViewById(R.id.cb05);
checkboxes[5] = this.findViewById(R.id.cb06);
save = this.findViewById(R.id.savebutton);
save.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
save_to_db();
}
});
logit = this.findViewById(R.id.logitbutton);
logit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mDBHlpr.logCheckBoxStatusForUser(current_user,checkboxes.length);
}
});
}
/**
* test to see if checkbox n (0-63) is set
* @param value_from_db_column the value extracted from the db that represents all checkboxes
* @param checkbox_to_check the checkbox to be tested
* @return true if checked else false
*/
public static boolean isCheckBoxNChecked(long value_from_db_column, int checkbox_to_check) {
return BigInteger.valueOf(value_from_db_column).testBit(checkbox_to_check);
}
/**
* Set checkbox n (0-63)
* @param current_checkbox the current checkbox status
* @param checkbox_to_set the checkbox to be set
* @return the amended checkbox status
*/
public long setCheckBox(long current_checkbox, int checkbox_to_set) {
return BigInteger.valueOf(current_checkbox).setBit(checkbox_to_set).longValue();
}
private void save_to_db() {
long checkboxes_to_save = 0L;
for (int i =0; i < checkboxes.length; i++) {
if (checkboxes[i].isChecked()) {
checkboxes_to_save = setCheckBox(checkboxes_to_save,i);
}
}
mDBHlpr.insertEntry(current_user,checkboxes_to_save);
}
}