/* 單個表列,多個表列,全部表列 */ -- 檢索單個列 SELECT prod_name FROM Products; SELECT prod_name FROM Products; SELECT prod_id,prod_name,prod_price FROM Products; SELECT * from Products; SELECT vend_id FROM Products; -- 使用 DISTINCT 只返回不一樣(具備惟一性)的值 -- DISTINCT 做用於全部的列 SELECT DISTINCT vend_id FROM Products; -- 表示從第5行開始返回3個數據 SELECT prod_name FROM Products LIMIT 3 OFFSET 5; -- 簡寫方式,從第3行開始返回5個數據 SELECT prod_name FROM Products LIMIT 3,5; /* 排序檢索數據 */ -- 注意 ORDER BY 必須放置查詢語句最後,否則會出現錯誤 SELECT prod_name FROM Products ORDER BY prod_name; -- 按多個列排序 SELECT prod_id,prod_price,prod_name FROM Products ORDER BY prod_price,prod_name; -- 按列位置排序,不用指定列名 SELECT prod_id,prod_price,prod_name FROM Products ORDER BY 2, 3; -- 降序排序 SELECT prod_id,prod_price,prod_name FROM Products ORDER BY prod_price DESC; -- 警告:DESC 只做用於當前列名,若是須要對多個列進行降序排序,必須對每一列指定 DESC 關鍵字 SELECT prod_id,prod_price,prod_name FROM Products ORDER BY prod_price DESC, prod_name DESC;