使用SQLite（Android）时，更改的行数（受影响的行）始终为1

Question

I have this SQLite table in my Android application:

CREATE TABLE " + TABLE_NAME + " (" +
        _ID + " INTEGER PRIMARY KEY AUTOINCREMENT" +
        COMMA + COLUMN_NAME_SID + " INTEGER" +
        COMMA + COLUMN_NAME_TITLE + " TEXT NOT NULL" +
        COMMA + COLUMN_NAME_IS_MINE + " BOOLEAN NOT NULL" +
        COMMA + COLUMN_NAME_CREATED_AT + " DATETIME" +
        COMMA + COLUMN_NAME_CODE + " TEXT UNIQUE" +
        COMMA + COLUMN_NAME_MSG + " INTEGER NOT NULL DEFAULT 0" +
        " );";

When I update a record with the same data, the number of changed rows (rows affected) is always 1.

SQLiteDatabase db = m_helper.getWritableDatabase();
String where = COLUMN_NAME_SID + "=" + sid;
ContentValues values = new ContentValues();
values.put(COLUMN_NAME_MSG, msg);
int rowsAffected = db.update(TABLE_NAME, values, where, null);
db.close();
// rowsAffected is always 1!

In other DBMS (like Mysql), when I perform an update with the same data on a specific record, the number of changed rows is 0. In SQLite on Android is different?

Answer 1

Maybe it just does not recognize if that data has actually been changed. Any query is counted as a change, even if the data is the same.

Well that's just the way they've implemented it. For instance, if you write something in IntellIJ IDE and delete it, it doesn't show the file as changed, but if you do it in Visual Studio, it does, unless you did CTRL+Z . It's just a different way of implementation.