#3. 操作檔案中的內容/記錄

往哪張表去插入 
insert into 表名指定欄位(id,name) 插入要加values(針對前面欄位插入)(2,mike);

insert into t1(id,name) values(2,'mike');

insert into t1 values(1,'egon1');

也可以用逗號隔開 同時插入多條記錄

insert into t1(id,name) values(1,'egon1'),(2,'egon2'),(3,'egon3');


如果預設不寫 按照表欄位順序 插入

增：insert into t1 values(1,'egon1'),(2,'egon2'),(3,'egon3');
 

檢視這張表哪個欄位
使用這條命令 前提是切換到t1的資料庫，如果在另外一個數據庫執行這條sql語句會報錯
select id,name from t1;

檢視指定資料庫的資料表的哪個欄位

select id,name from db1.t1;

mysql> insert into t1(id,name) values(2,'mike');
Query OK, 1 row affected (0.00 sec)

mysql> desc t1;
+-------+---------+------+-----+---------+-------+
| Field | Type    |
 
 Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | YES  |     | NULL    |       |
| name  | char(6) | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
2 rows in set (0.00 sec)

mysql> select id,name from t1;
+------+------+
 

| id   | name |
+------+------+
|    2 | mike |
+------+------+
1 row in set (0.00 sec)

mysql> select id,name from db1.t1;
+------+------+
| id   | name |
+------+------+
|    2 | mike |
+------+------+
1 row in set (0.00 sec)

* 代表所有欄位

查：select * from t1; 

mysql> insert into t1 values(1,'jack'),(3,'ben'),(4,'peter');
Query OK, 3 rows affected (0.00 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> select * from db1.t1;
+------+-------+
| id   | name  |
+------+-------+
|    2 | mike  |
|    1 | jack  |
|    3 | ben   |
|    4 | peter |
+------+-------+
4 rows in set (0.00 sec)

update t1 set name='sb' ;

最好指定改哪一條記錄
改：update t1 set name='sb' where id=2; 

mysql> update db1.t1 set name='alex' where id =1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> desc t1;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | YES  |     | NULL    |       |
| name  | char(6) | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
2 rows in set (0.06 sec)

mysql> 
mysql> select * from t1;
+------+-------+
| id   | name  |
+------+-------+
|    2 | mike  |
|    1 | alex  |
|    3 | ben   |
|    4 | peter |
+------+-------+
4 rows in set (0.00 sec)

把t1 表刪了
delete from t1 
刪：delete from t1 where id=1;

mysql> delete from t1 where id=2;
Query OK, 1 row affected (0.00 sec)

mysql> select * from t1;
+------+-------+
| id   | name  |
+------+-------+
|    1 | alex  |
|    3 | ben   |
|    4 | peter |
+------+-------+
3 rows in set (0.00 sec)