如何让dbf数据库命令栏显示多条命令？

mysql数据库基本命令---多条数据的同时 *** 作

添加主键

mysql>alter table info add primary key(id)

Query OK, 0 rows affected (0.07 sec)

Records: 0 Duplicates: 0 Warnings: 0

mysql>desc info#查看主键

+--------+--------------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+--------+--------------+------+-----+---------+-------+

| id | int(11) | NO | PRI | NULL | | #显示出主键

| name | char(6) | YES | | NULL | |

| score | decimal(5,2) | YES | | NULL | |

| age | int(4) | YES | | NULL | |

| hobbly | int(4) | YES | | NULL | |

+--------+--------------+------+-----+---------+-------+

5 rows in set (0.00 sec)

添加外键

alter table info add constraint FK_ID foreign key(hobbly) REFERENCES hy(id)

mysql>show index from info\G#查看外键

* 2. row *

Table: info

Non_unique: 1

Key_name: FK_ID #外键添加成功

Seq_in_index: 1

Column_name: hobbly

Collation: A

Cardinality: 3

Sub_part: NULL

Packed: NULL

Null: YES

Index_type: BTREE

Comment:

Index_comment:

2 rows in set (0.00 sec)

表格同时修改个字段(不同表列内容)

update info set age=23,num=44 where id=2

mysql>select * from info

+----+--------+-------+-----------+------+------+

| id | name | score | hobbly | age | num |

+----+--------+-------+-----------+------+------+

| 1 | zl | 88 | 看书 | 33 | NULL |

| 2 | 李四 | 68 | 上网 | 23 | 44 | #成功修改

| 3 | 王四 | 68 | 看电视 | NULL | NULL |

+----+--------+-------+-----------+------+------+

3 rows in set (0.00 sec)

同时增加多个字段

mysql>alter table info add column age int,add column num int

Query OK, 0 rows affected (0.05 sec)

Records: 0 Duplicates: 0 Warnings: 0

mysql>desc info#查看表结构

+--------+----------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+--------+----------+------+-----+---------+-------+

| id | int(11) | NO | PRI | NULL | |

| name | char(4) | YES | | NULL | |

| score | char(6) | YES | | NULL | |

| hobbly | char(10) | YES | | NULL | |

| age | int(11) | YES | | NULL | |

| num | int(11) | YES | | NULL | |

+--------+----------+------+-----+---------+-------+

同时删除多个字段

mysql>alter table info drop column age,drop column num

Query OK, 0 rows affected (0.05 sec)

Records: 0 Duplicates: 0 Warnings: 0

mysql>select * from info

+----+--------+-------+-----------+

| id | name | score | hobbly |

+----+--------+-------+-----------+

| 1 | zl | 88 | 看书 |

| 2 | 李四 | 68 | 上网 |

| 3 | 王四 | 68 | 看电视 |

+----+--------+-------+-----------+

同时删除多个记录条数(多行)

mysql>delete from info where id in (3,4)

Query OK, 2 rows affected (0.00 sec)

mysql>select * from info

+----+--------+-------+--------+

| id | name | score | hobbly |

+----+--------+-------+--------+

| 1 | zl | 88 | 看书 |

| 2 | 李四 | 68 | 上网 |

| 5 | kl | 88 | 游泳 |

+----+--------+-------+--------+

同时查看多条指定记录(行)

mysql>select * from info where id in (3,4)

+----+--------+-------+-----------+

| id | name | score | hobbly |

+----+--------+-------+-----------+

| 3 | 王四 | 68 | 看电视 |

| 4 | ll | 67 | 看书 |

.dbf 是一种特殊的文件格式，表示数据库文件，Foxbase,Dbase,Visual FoxPro,等数据库处理系统所产生的数据库文件。

创建方法：

.dbf文件是数据表，.dbc文件是数据库，在VFP中，点击文件菜单中的新建菜单项，打开新建对话框，在内选.dbf单选项后，点新建按钮即可打开创建对话框，根据提示就可建了。

打开方式 ：

DBF Viewer Pro 是一个用于 Windows 下的 DBF 数据库文件管理器。

可用FOXPRO打开 。

还可用EXCEL进行打开。

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