Oracle判斷查詢結果是否為空的方法主要有以下幾種：
SELECT COUNT(*) FROM table_name WHERE condition;
SELECT column_name FROM table_name WHERE EXISTS (SELECT * FROM table_name WHERE condition);
SELECT column_name FROM table_name WHERE column_name IS NULL;
SELECT column_name FROM table_name WHERE condition AND ROWNUM = 1;
以上是Oracle中判斷查詢結果是否為空的幾種常用方法，根據具體的需求可以選擇合適的方法使用。
