查询数据表的全部内容
mysql> show tables;#查看当前数据库下的全部表
+--------------------+
| Tables_in_ceshi_ku |
+--------------------+
| biao |
| ceshi_biao |
+--------------------+
2 rows in set (0.00 sec)
mysql> select * from biao;#查看该表全部的内容，*代表通配符，在这里是代表全部的列
+------+-----------+--------+----------+--------+
| id | name | gender | gongsi | gongzi |
+------+-----------+--------+----------+--------+
| 1 | ma yun | n | tao bao | 6000.5 |
| 2 | xiao hong | v | xin lang | 5000.7 |
| 3 | xiao ming | n | bai du | 3000.4 |
| 4 | li si | n | sou hu | 9000.2 |
| 5 | lao wang | NULL | wang yi | 1000.5 |
| 6 | xiao li | NULL | ku gou | 700.1 |
+------+-----------+--------+----------+--------+
6 rows in set (0.00 sec)
查询数据表的全部列、部分行
mysql> select * from biao where id>4;#查询全部列。部分行。即id大于4的行
+------+----------+--------+---------+--------+
| id | name | gender | gongsi | gongzi |
+------+----------+--------+---------+--------+
| 5 | lao wang | NULL | wang yi | 1000.5 |
| 6 | xiao li | NULL | ku gou | 700.1 |
+------+----------+--------+---------+--------+
2 rows in set (0.02 sec)
查询数据表的部分列、全部行
mysql> select name,gongzi from biao;#查询部分列，即"name"和"gongzi"列。之间用","隔开。选择全部行
+-----------+--------+
| name | gongzi |
+-----------+--------+
| ma yun | 6000.5 |
| xiao hong | 5000.7 |
| xiao ming | 3000.4 |
| li si | 9000.2 |
| lao wang | 1000.5 |
| xiao li | 700.1 |
+-----------+--------+
6 rows in set (0.02 sec)
查询数据表的部分列、部分行
mysql> select name from biao where gongzi>3000;#选择部分列。即"name"列，也能够多个列。然后选择工资>3000的行
+-----------+
| name |
+-----------+
| ma yun |
| xiao hong |
| xiao ming |
| li si |
+-----------+
4 rows in set (0.00 sec)