建立資料庫和建立表請看
選擇zhaochao資料庫，並檢視user表中字段如下：
insert into user (id,username,userpasswd) values (3,'趙超','zhaochao');
insert into user values (4,'趙雲','zhaoyun');
將自身插入自身
| 3 | 趙超 | zhaochao |
| 4 | 趙雲 | zhaoyun |
+------+----------+------------+
4 rows in set (0.00 sec)
mysql> delete from user where id=4;
query ok, 1 row affected (0.03 sec)
mysql> select * from user;
+------+----------+------------+
| id | username | userpasswd |
+------+----------+------------+
| 1 | admin | admin |
| 2 | zhaochao | zhaochao |
| 3 | 趙超 | zhaochao |
+------+----------+------------+
3 rows in set (0.00 sec)
update user set username='root' where id=1;+------+----------+------------+
| id | username | userpasswd |
+------+----------+------------+
| 1 | admin | admin |
| 2 | zhaochao | zhaochao |
| 3 | 趙超 | zhaochao |
+------+----------+------------+
3 rows in set (0.00 sec)
mysql> update user set username='root' where id=1;
query ok, 1 row affected (0.03 sec)
rows matched: 1 changed: 1 warnings: 0
mysql> select * from user;
+------+----------+------------+
| id | username | userpasswd |
+------+----------+------------+
| 1 | root | admin |
| 2 | zhaochao | zhaochao |
| 3 | 趙超 | zhaochao |
+------+----------+------------+
3 rows in set (0.00 sec)
select id,username,userpasswd from user;+------+----------+------------+
| id | username | userpasswd |
+------+----------+------------+
| 1 | root | admin |
| 2 | zhaochao | zhaochao |
| 3 | 趙超 | zhaochao |
+------+----------+------------+
3 rows in set (0.00 sec)
select id '使用者編號',username '使用者名稱',userpasswd '密碼' from user a where a.id=1 ;+----------+--------+-------+
| 使用者編號 | 使用者名稱 | 密碼 |
+----------+--------+-------+
| 1 | root | admin |
+----------+--------+-------+
1 row in set (0.00 sec)
select id,username,userpasswd from user limit 1,2;+------+----------+------------+
| id | username | userpasswd |
+------+----------+------------+
| 2 | zhaochao | zhaochao |
| 3 | 趙超 | zhaochao |
+------+----------+------------+
2 rows in set (0.00 sec)
mysql增刪改查效果 mysql增刪改查
檢視所有資料庫 mysql show databases 建立乙個庫ghd並指定字符集為utp8 mysql create database ghd charset utf8 檢視mysql支援的字符集 mysql show char set 建立乙個表，並設定id為主鍵 create table ...
mysql增刪改查擴充套件 MySQL增刪改查
1 插入 insert 1 insert into 表名 values 值1 值2 例子 insert into t1 values zengsf 23 fengshao 22 2 insert into 表名 欄位1,values 值1 例子 insert into t1 name values ...
mysql建刪改查 MySQL增刪改查
登入mysql mysql u root p 密碼 建立使用者 mysql insert into mysql.user host,user,password values localhost test password 1234 這樣就建立了乙個名為 test 密碼為 1234 的使用者。注意 此...