在android中为treeview创建数据库

public class DatabaseHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "treeview.db";
    private static final int DATABASE_VERSION = 1;

    private static final String CREATE_TABLE = "CREATE TABLE IF NOT EXISTS treeview " +
            "(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, parent_id INTEGER)";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // 如果需要升级数据库，可以在这里处理
    }
}

DatabaseHelper dbHelper = new DatabaseHelper(context);
SQLiteDatabase db = dbHelper.getWritableDatabase();

public class TreeNode {
    private int id;
    private String name;
    private int parentId;

    // 构造方法、getter和setter等省略
}

public void insertNode(TreeNode node) {
    ContentValues values = new ContentValues();
    values.put("name", node.getName());
    values.put("parent_id", node.getParentId());
    db.insert("treeview", null, values);
}

public void deleteNode(int nodeId) {
    db.delete("treeview", "id=?", new String[]{String.valueOf(nodeId)});
}

public void updateNode(TreeNode node) {
    ContentValues values = new ContentValues();
    values.put("name", node.getName());
    values.put("parent_id", node.getParentId());
    db.update("treeview", values, "id=?", new String[]{String.valueOf(node.getId())});
}

public List<TreeNode> queryNodes(int parentId) {
    List<TreeNode> nodes = new ArrayList<>();
    Cursor cursor = db.query("treeview", null, "parent_id=?", new String[]{String.valueOf(parentId)}, null, null, null);
    if (cursor != null) {
        while (cursor.moveToNext()) {
            TreeNode node = new TreeNode();
            node.setId(cursor.getInt(cursor.getColumnIndex("id")));
            node.setName(cursor.getString(cursor.getColumnIndex("name")));
            node.setParentId(cursor.getInt(cursor.getColumnIndex("parent_id")));
            nodes.add(node);
        }
        cursor.close();
    }
    return nodes;
}