Android中BaseColumns有什么用

Android中的BaseColumns是一个接口，它定义了数据库表中的基本列名和常量。它主要用于简化数据库操作和确保数据库表的一致性。在本文中，我们将详细介绍BaseColumns的用途，并提供一个案例代码来说明它的具体应用。

java
public class StudentContract {
    public static final class StudentEntry implements BaseColumns {
        public static final String TABLE_NAME = "students";
        public static final String COLUMN_NAME = "name";
        public static final String COLUMN_AGE = "age";
        public static final String COLUMN_GENDER = "gender";
    }
}

java
public class StudentDbHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "students.db";
    private static final int DATABASE_VERSION = 1;
    public StudentDbHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        String SQL_CREATE_STUDENTS_TABLE = "CREATE TABLE " + StudentEntry.TABLE_NAME + " ("
                + StudentEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + StudentEntry.COLUMN_NAME + " TEXT NOT NULL, "
                + StudentEntry.COLUMN_AGE + " INTEGER NOT NULL, "
                + StudentEntry.COLUMN_GENDER + " TEXT NOT NULL);";
        db.execSQL(SQL_CREATE_STUDENTS_TABLE);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // 省略升级逻辑
    }
}