查詢數據表的全部內容
mysql> show tables;#查看當前數據庫下的所有表
+--------------------+
| Tables_in_ceshi_ku |
+--------------------+
| biao |
| ceshi_biao |
+--------------------+
2 rows in set (0.00 sec)
mysql> select * from biao;#查看該表所有的內容，*代表通配符，在這裏是代表所有的列
+------+-----------+--------+----------+--------+
| 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)
查詢數據表的所有列、部分行
mysql> select * from biao where id>4;#查詢所有列，部分行，即id大於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)
查詢數據表的部分列、所有行
mysql> select name,gongzi from biao;#查詢部分列，即"name"和"gongzi"列，之間用","隔開。選擇所有行
+-----------+--------+
| 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)
查詢數據表的部分列、部分行
mysql> select name from biao where gongzi>3000;#選擇部分列，即"name"列，也可以多個列。然後選擇工資>3000的行
+-----------+
| name |
+-----------+
| ma yun |
| xiao hong |
| xiao ming |
| li si |
+-----------+
4 rows in set (0.00 sec)
