????????
????1.????????
????2.????????
????3.?????
????4.??????
????????????????students
????????????????class1
?????????????
????id ???? ?????? ?????λ SMALLINT????
????name VARCHAR(30)???? ??? ?
????school VARCHAR(30) ??? ????chengdu college
???????????￡?
????1.?????????
????mysql> CREATE DATABASE students;
????Query OK?? 1 row affected (0.07 sec)
????2.?????????
????mysql> USE students;
????Database changed
????3.?????
mysql> CREATE TABLE class1 (
-> id SMALLINT UNSIGNED AUTO_INCREMENT ??
-> name VARCHAR(30) NOT NULL UNIQUE KEY ??
-> school VARCHAR(30) DEFAULT 'chengdu_collage' ??
-> PRIMARY KEY(id)
-> );
Query OK?? 0 rows affected (0.09 sec)
????4.?????
mysql> DESC class1;
+--------+----------------------+------+-----+-----------------+----------------+
| Field  | Type                 | Null | Key | Default         | Extra          |
+--------+----------------------+------+-----+-----------------+----------------+
| id     | smallint(5) unsigned | NO   | PRI | NULL            | auto_increment |
| name   | varchar(30)          | NO   | UNI | NULL            |                |
| school | varchar(30)          | YES  |     | chengdu_collage |                |
+--------+----------------------+------+-----+-----------------+----------------+
3 rows in set (0.00 sec)
????1.????(INSERT)
1.INSERT INTO tb_name [(col_name...)] {VALUES|VALUE}({expr | DEFAULT}??....)??(...)...
?????
mysql> INSERT INTO class1 (name) VALUES ('john');
Query OK?? 1 row affected (0.01 sec)
mysql> INSERT INTO class1 VALUES (DEFAULT??'jobs'??'chengdu_agricultural_college');
Query OK?? 1 row affected (0.01 sec)
2.INSERT INTO tb_name SET col_name = {expr | DEFAULT}??...
?????
mysql> INSERT INTO class1 SET name='tom';
Query OK?? 1 row affected (0.02 sec)
mysql> INSERT INTO class1 SET name='lues'??school='chengdu_agricultural_college';
Query OK?? 1 row affected (0.01 sec)
????2.???(UPDATE)
1.UPDATE [LOW_PRIORITY] [IGNORE] table_reference
SET col_name1={expr1|DEFAULT} [?? col_name2={expr2|DEFAULT}] ...
?????
mysql> UPDATE class1
-> SET name='lues2' WHERE name='lues';
Query OK?? 1 row affected (0.07 sec)
Rows matched: 1  Changed: 1  Warnings: 0
????3.???(DELETE)
1.DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name
[WHERE where_condition]
?????
mysql> DELETE FROM class1 WHERE name='lues2';
Query OK?? 1 row affected (0.01 sec)
????4.???(SELECT)
1.?????
mysql> SELECT * FROM class1;
+----+------+------------------------------+
| id | name | school                       |
+----+------+------------------------------+
|  1 | john | chengdu_collage              |
|  2 | jobs | chengdu_agricultural_college |
|  3 | tom  | chengdu_collage              |
+----+------+------------------------------+
3 rows in set (0.00 sec)
2.???????????
mysql> SELECT * FROM class1 WHERE id > 1;
+----+------+------------------------------+
| id | name | school                       |
+----+------+------------------------------+
|  2 | jobs | chengdu_agricultural_college |
|  3 | tom  | chengdu_collage              |
+----+------+------------------------------+
2 rows in set (0.00 sec)
3.?????????
mysql> SELECT * FROM class1 GROUP BY school DESC;
+----+------+------------------------------+
| id | name | school                       |
+----+------+------------------------------+
|  1 | john | chengdu_collage              |
|  2 | jobs | chengdu_agricultural_college |
+----+------+------------------------------+
2 rows in set (0.00 sec)
4.??????????
mysql> SELECT * FROM class1 ORDER BY id DESC;
+----+------+------------------------------+
| id | name | school                       |
+----+------+------------------------------+
|  3 | tom  | chengdu_collage              |
|  2 | jobs | chengdu_agricultural_college |
|  1 | john | chengdu_collage              |
+----+------+------------------------------+
3 rows in set (0.00 sec)