MySQL中數據表的查操作
阿新 • • 發佈:2019-03-11
fix where ack tps tables 內容 link 部分 lang
查詢數據表的全部內容
mysql> show tables;#查看當前數據庫下的全部表 +--------------------+ | Tables_in_ceshi_ku | +--------------------+ | biao | | ceshi_biao | +--------------------+ 2 rows in set (0.00 sec) mysql> select * from biao;#查看該表全部的內容。*代表通配符。在這裏是代表全部的列 +------+-----------+--------+----------+--------+ | 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)
查詢數據表的全部列、部分行
mysql> select * from biao where id>4;#查詢全部列,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、全部行
mysql> select name,gongzi from biao;#查詢部分列,即"name"和"gongzi"列,之間用","隔開。選擇全部行 +-----------+--------+ | 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。也能夠多個列。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)
MySQL中數據表的查操作