/*


insert into join_teacher values(4, '孫武', 'male');
insert into join_class values(4,'php0505','202');
連結查詢
先將所有資料鏈接起來再進行查詢；
內連線，外連線，自然連結


*/




--------------------------------------內連線------------------------------------
-- 資料內部的內連線  連結的多個數據必須存在
-- mysql 中預設是 inner join 可以寫成 join
-- on 跟連結條件 也可以用 where
  table_left inner join table_right on ;


-- 比較標準的語法 on 連結條件， where 過濾條件
select t.t_name, tc.begin_date, tc.days from join_teacher t inner join join_teacher_class tc on t.id = tc.t_id where days > 15;


select t.t_name, tc.begin_date, tc.days from join_teacher t cross join join_teacher_class tc;


select id , days, t_name from join_teacher inner join join_teacher_class using (id);


--------------------------------------外連線------------------------------------


-- 如果負責連結的一個或多個數據不存在 外連線 可以有連結不到的資料
--  外連線不能用where作為連結條件，但可以使用on 和 using
select t.t_name, tc.begin_date, tc.days from join_teacher t left outer join join_teacher_class tc on t.id = tc.t_id;


-- 當欄位重名時寫表名
-- 左外連線
-- 在連線時，如果出現左邊表，資料鏈接不到右邊表的情況，則左邊表資料保留，
-- 如果出現右邊表的資料左邊表沒有，右邊表的資料丟棄
-- outer join  outer 可以省略
select t.id as t_id, tc.id as tc_id, t.t_name, tc.begin_date, tc.days from 
join_teacher t left join join_teacher_class tc on t.id = tc.t_id;




-- 右外連線
select t.id as t_id, tc.id as tc_id, t.t_name, tc.begin_date, tc.days from 
join_teacher t right join join_teacher_class tc on t.id = tc.t_id;




--------------------------------------自然連結-----------------------------------------------


/*
通過mysql自己的判斷選用連線型別
內：natural join
外：left natural join
right natural join


連線時支援多表同時連線
*/


/*
outfile 操作
dumpfile
*/
--  設定資料格式
-- fields terminated
-- lines terminated
select * from teacher;


select * into outfile 'e:/one.txt' from teacher;
select * into outfile 'e:/one.txt' fields terminated by ',' from teacher 


select * from dumpfile 'e:oe' from teacher;


-----------------------------------插入資料------------------------------------------------------




insert into table_name(column_name) values(value);


insert into table_name set column_name1=value2, column_name2=value2;


insert into table_name(column_name, column_name2) values
(value1,value2),
(value1,value2);


-- 插入資料時主鍵衝突
--預設報錯，表示不會插入
-- 可以insert插入 on duplicate key update 不加set;
insert into table_name(id, t_name)values(1,'ji')
on duplicate key update t_name='ji';


-- 用select結果作為插入資料
insert into table_name1 (column_name1, column_name2) select column_name1,column_name2 from table_name2;




-- replace 主鍵不衝突直接插入，否則替換
replace into teacher values(1,'han','dd', 90);
    alter table table_name drop primary key;-- 如果主鍵自動增長，執行不成功


-- load data infile; 在匯出時將主鍵刪除掉，匯入時再新建主鍵




-----------------------------------刪除資料------------------------------------------------------


--delete 允許使用limit 限制刪除的條數 limit 配合order by 使用
delete from table_name order by days limit 10;


delete from one, two using one join two on one.public_field = two.public_field;


-- 清空表
truncate 
-- 類似 
delete from table
-----------------------------------更新資料------------------------------------------------------
update one join two on one_public_field  = two_public_field set one_data=value where id = value;


------------------------------------檢視操作--------------------------------------------------------
create table info_teacher(
id int primary key auto_increment,
t_name varchar(20),
salary decimal(10,2)
);


insert into info_teacher values
(null, '韓信',180.90),
(null, '李白', 230.65),
(null, '韓飛', 159.03);


create view v_teacher as select id, t_name from info_teacher;
insert into v_teacher values(null, '江湖');


+----+--------+
| id | t_name |
+----+--------+
|  1 | 韓信   |
|  2 | 李白   |
|  3 | 韓飛   |
|  4 | 江湖   |
+----+--------+
4 rows in set (0.00 sec)


mysql> select * from info_t
+----+--------+--------+
| id | t_name | salary |
+----+--------+--------+
|  1 | 韓信   | 180.90 |
|  2 | 李白   | 230.65 |
|  3 | 韓飛   | 159.03 |
|  4 | 江湖   |   NULL |
+----+--------+--------+
4 rows in set (0.00 sec)
/*
檢視是動態的，只儲存了一條sql語句；2014/3/11
drop view v_teacher;
*/


drop view if exists v_teacher;


alter view v_name as select * from info_teacher;