Android: How to change value of sqlite column

Question

I am relatively new to using sqlite in the android world and I currently I my sqlite database set up like the following:

db.execSQL("CREATE TABLES " + DATABASE_TABLE + " (" + KEY_ROWID
                    + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_LOCKERNUMBER
                    + " TEXT NOT NULL, " + KEY_STATUS + " INTEGER DEFAULT 0, "
                    + KEY_PIN + " INTEGER DEFAULT 0);");

And I have the following methods to insert data into the database:

// function to add lockers to database
    public long createLockerEntry(String lockerNumber, int status) {
        ContentValues cv = new ContentValues();
        cv.put(KEY_LOCKERNUMBER, lockerNumber);
        cv.put(KEY_STATUS, status);
        return ourDatabase.insert(DATABASE_TABLE, null, cv);
    }

    // function to create a pin for the locker
    public void createPin(String lockerNumber, int pin, int status) {

    }

    // function to remove pin
    public void removePin(String lockerNumber, int pin, int status) {

    }

My intentions are to add a pin number for a certain locker number to the KEY_PIN column within the method Create pin and then change the status value to 1. I would assume I would use the where clause statement but I am not completely sure about the syntax or if that is the write approach. Any suggestions?

Answer 1

The method you want is update()
You can read about it by searching for "update" on this page:

http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html

One way to use this would be:

// function to create a pin for the locker
public void createPin(tring lockerNumber, int pin, int status) {
    ContentValues cv = new ContentValues()
    cv.put(KEY_PIN, pin);
    cv.put(KEY_STATUS, status);
    ourDatabase.update(DATABASE_TABLE, cv, KEY_LOCKERNUMBER + " = ?" 
                  , new String[] {lockerNumber});
}

Answer 2

Here's an example where I toggle the value of an entry. It is an int value used as binary (ie 1 or 0). The two methods checkAsWildTest, and uncheckAsWildTest.

public void checkAsWildTest(Cursor c, int val) {

    assertDbOpen();
    String[] _params = { String.valueOf(c.getInt(ID_COLUMN)) };
    //next 4 lines are just for debug
    log(".uncheckAsWildTest(), " + "c.getCount() = " + c.getCount());
    log("row selected = " + c.getInt(ID_COLUMN));
    log("cursor content: " + c.getString(ANSWERS_RESPONSE_COLUMN));
    log("cursor columns" + Arrays.toString(c.getColumnNames()));

    ContentValues cv = new ContentValues();
    cv.put(KEY_ANSWERS_CHECKED, val);
    db.update(ANSWERS_TABLE, cv, "_id=?", _params);
}

public void uncheckAsWildTest(Cursor c) {
    assertDbOpen();
    int unchecked = 0;
    String[] _params = { String.valueOf(c.getInt(ID_COLUMN)) };
    //next 4 lines are just for debug
    log(".uncheckAsWildTest(), " + "c.getCount() = " + c.getCount());
    log("column selected = " + c.getInt(ID_COLUMN));
    log("cursor content: " + c.getString(ANSWERS_RESPONSE_COLUMN));
    log("cursor columns" + Arrays.toString(c.getColumnNames()));

    ContentValues cv = new ContentValues();
    cv.put(KEY_ANSWERS_CHECKED, unchecked);
    db.update(ANSWERS_TABLE, cv, "_id=?", _params);
}

I believe you can work with this, and modify it for your purposes.