初探SchemaUpdate工具
以前开发的时候都是根据文档中的内容来建立数据库然后再启动项目。开发之前建立数据库在开发过程中会遇到一些不必要的麻烦，使得我们不得不以数据库为中心开发，数据库设计好了开发起来容易些，如果数据库设计不好那么给我们的开发会带来多大的麻烦啊!为了解决这个问题在我采用领域驱动设计。
领域驱动设计就是先编写持久化类和映射文件，然后使用SchemaExport工具生成数据库架构。我个人的理解是先建立对象模型，然后根据对象模型来生成数据库。这也是面向对象开发的步骤和我们传统的开发有点背。
NHibernate的hbm2dll提供SchemaExport工具，这个工具可以根据对象模型自动生成数据库，废话就少说了看下面的实例吧，代码是最有说服力的。
首先写持久化类
代码
1
2
namespace
DDDTest
3
4
5
[DisplayName(
"
员工
"
)]
6
[Class(Table
=
"
Employees
"
, NameType
=
typeof
(Employee), Schema
=
"
dbo
"
)]
7
public
class
Employee : DomainModel
8
{
9
public
Employee()
10
{
11
12
}
13
14
[DisplayName(
"
编号
"
)]
15
[Id(Name
=
"
ID
"
, Column
=
"
EmployeeID
"
)]
16
[Generator(
1
, Class
=
"
native
"
)]
17
virtual
public
int
ID {
get
;
set
; }
18
19
[DisplayName(
"
姓名
"
)]
20
[Property(Length
=
200
, NotNull
=
true
, Unique
=
true
)]
21
virtual
public
string
Name {
get
;
set
; }
22
23
[DisplayName(
"
生日
"
)]
24
[Property(NotNull
=
false
)]
25
virtual
public
DateTime
?
Birthday {
get
;
set
; }
26
27
}
28
}
29
然后写XML文件按照新映射架构数据库(真正开发的时候XML可以不用写可以用hibernate.cfg.xml我这里只是一个演示)
代码
<?
xml version
=
"
1.0
"
encoding
=
"
utf-8
"
?>
<!--
This template was written to work with NHibernate.Test.
Copy the template to your NHibernate.Test project folder and rename it
in
hibernate.cfg.xml and change it
for
your own use before compile tests
in
VisualStudio.
-->
<!--
This
is
the System.Data.dll provider
for
SQL Server
-->
<
hibernate
-
configuration xmlns
=
"
urn:nhibernate-configuration-2.2
"
>
<
session
-
factory name
=
"
NHibernate.Test
"
>
<
property name
=
"
connection.driver_class
"
>
NHibernate.Driver.SqlClientDriver
</
property
>
<
property name
=
"
connection.connection_string
"
>
Server
=
(local);initial catalog
=
FF;Integrated Security
=
SSPI
</
property
>
<
property name
=
"
adonet.batch_size
"
>
10
</
property
>
<
property name
=
"
show_sql
"
>
false
</
property
>
<
property name
=
"
dialect
"
>
NHibernate.Dialect.MsSql2005Dialect
</
property
>
<
property name
=
"
use_outer_join
"
>
true
</
property
>
<
property name
=
"
command_timeout
"
>
60
</
property
>
<
property name
=
"
query.substitutions
"
>
true
1
,
false
0
, yes
'
Y
'
, no
'
N
'
</
property
>
<
property name
=
"
proxyfactory.factory_class
"
>
NHibernate.ByteCode.LinFu.ProxyFactoryFactory, NHibernate.ByteCode.LinFu
</
property
>
</
session
-
factory
>
</
hibernate
-
configuration
>
最后一步就是用SchemaUpdate工具生成数据库了
代码
1
public
static
void
CreadDB()
2
{
3
var connectionString
=
Configuration.GetProperty(
"
connection.connection_string
"
);
4
5
SqlServer05Helper.ReCreateDatabase(connectionString);
6
SqlServer05Helper.CreateSchemasOnDbo(connectionString, Configuration.GetAllSchemas());
7
SchemaExport export
=
new
SchemaExport(Configuration);
8
export.Create(
true
,
true
);
9
10
}
SqlServer05Helper.ReCreateDatabase(connectionString);
SqlServer05Helper.CreateSchemasOnDbo(connectionString, configuration.GetAllSchemas());
这俩句用了一个扩展类SqlServer05Helper.CS主用是生成一个数据库的架构
var schemaExport = new SchemaExport(configuration);
schemaExport.Create(true, true)
这俩句主要就是生成表的。
在这里有主要写了下SchemaExport工具怎样生成数据库，SchemaExport还可以更新删除数据库。