What is the use of BaseColumns in Android

Question

What is the use of implementing a class from BaseColumns in Android?

Answer 1

The BaseColumn interface only provides the column names _ID and _COUNT. You must still specify columns that use them when constructing tables. For example, to create a column using the column name _ID you might do the following:

public static final String CREATE_TABLE =
    "CREATE TABLE IF NOT EXISTS " + TABLE_NAME + " ("
    + _ID + " INTEGER PRIMARY KEY, "
    + USERNAME + " TEXT NOT NULL, "
    + PASSWORD + " TEXT NOT NULL, "
    + EMAIL + " TEXT NOT NULL UNIQUE)";