SELECT 1. AS 的應用 SELECT depart_class AS 班級,student_no AS 學號,student_name AS 姓名, address AS 地址 FROM stmd; select depart_clASs AS 班級,student_no AS 學號,student_name AS 姓名, address AS 地址 FROM stmd ORDER BY 學號; 2. LIKE 的應用 萬用字元 % 表匹配全部 _ 表匹配一個字元 SELECT * FROM stmd WHERE student_no LIKE "100%"; SELECT * FROM stmd WHERE student_name LIKE "林%";
1. UPDATE stmd SET student_no="10014D001"; 會將所有學號都改成 10014D001 2. UPDATE stmd SET student_name="張三豐" WHERE student_no="10014D001"; 會將學號 10014D001 的姓名欄更改 3. UPDATE stmd set depart_class= concat(SUBSTR(depart_class,1,4),"2",SUBSTR(depart_class,6,1)) WHERE depart_class LIKE "____1_"; 會將年級升上一級
建立資料表 包括 depart_class student_no student_name score1 score2 score3 total 以INSERT INTO stmd VALUES("164D11","1014D001","張三",60,70,80,0); 輸入四班12筆資料
1. DELETE FROM stmd; 刪除所有紀錄(非常危險,應小心使用) 2. DELETE FROM stmd WHERE student_no="10014D001"; 會將學號 10014D001 整筆資料刪除 3. DELETE FROM stmd WHERE depart_class="164D21"; 會將班級="164D21"的所有資料刪除