CodeSmith 是一种语法类似于asp.net的基于模板的代码生成器，程序可以自定义模板，从而减少重复编码的劳动量，提高效率。
安装CodeSmith 2.6注册后发现有两个可运行程序CodeSmith Studio.exe和CodeSmith Explorer.exe
CodeSmith Studio.exe用来创建自定义模板
CodeSmith Explorer.exe用来导入模板并且生成代码
打开 CodeSmith Studio.exe，新建一个C#模板。发现有如下类似与asp.net的标识符号
<% %>
<%= %>
<%@ %>
<script runat="template"> </script>
下面通过简单的例子说明如何用 CodeSmith 创建模板并生成代码
新建一个空的txt文件，在文件上部输入如下一个CodeTemplate指示,Language 和TargetLanguage分别代表模板语言和创建代码语言，
然后声明几个变量，用来为了能够在以后生成的代码嵌入，这里声明了三个名为NameSpace,ClassName,Contxt的变量。其他参数一目了然就不再说明了，
<%@ Property Name="NameSpace" Type="String" Category="Context" Description="The namespace to use for this class" %> <%@ Property Name="ClassName" Type="String" Category="Context" Description="The name of the class to generate" %> <%@ Property Name="DevelopersName" Type="String" Category="Context" Description="The name to include in the comment header" %>
接下来建立将要生成代码的框架，在适当位置引用刚刚声明的变量名
using System; namespace <%=NameSpace %> { /// <summary> /// Summary description for <%=ClassName %>. /// </summary> public class <%=ClassName %> { public <%=ClassName %>() { } } }
最后，打开CodeSmith Explorer.exe，加载此模板,并且在属性对话框中任意更改声明的变量名，按Generate按钮生成合适的代码
以上简单的说明了CodeSmith的功能
下面看看在数据库访问中它是如何最小化我们的工作的
在这里我们要用到CodeSmith API中一个叫SchemaExplorer的组件，它提供了一系列类来操作数据库的框架,我们可以用它来创建表和存储过程，得到字段类型，字段名等。
如下是更新NorthWind数据库中orders表记录的存储过程,我们来看看如何自动生成它
CREATE PROCEDURE dbo.UpdateOrders
@OrderID int,
@CustomerID nchar(5),
@EmployeeID int,
@OrderDate datetime,
@RequiredDate datetime,
@ShippedDate datetime,
@ShipVia int,
@Freight money,
@ShipName nvarchar(40),
@ShipAddress nvarchar(60),
@ShipCity nvarchar(15),
@ShipRegion nvarchar(15),
@ShipPostalCode nvarchar(10),
@ShipCountry nvarchar(15)
AS
UPDATE [Orders] SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE
[OrderID] = @OrderID第一步还是创建一个CodeTemplate指示，注意 TargetLanguage属性改为了T-SQL，因为创建的SQL语言代码
<%@ CodeTemplate Language="C#" TargetLanguage="T-SQL" Description="Generates a update stored procedure." %>
然后加载SchemaExplorer组件，并导入 SchemaExplorer命名空间，看这里是不是和asp.net很像
<%@ Assembly Name="SchemaExplorer" %> <%@ Import Namespace="SchemaExplorer" %>
接下来声明变量,因为要从数据库表中读取框架所以 Type 属性为SchemaExplorer.TableSchema
<%@ Property Name="SourceTable" Type="SchemaExplorer.TableSchema" Category="Context" Description="Table that the stored procedures should be based on." %>
下面就要写实际将要输出代码部分的模板了。
先写存储过程的第一行 ,<%%>内为引用前面声明变量名，代表表名
CREATE PROCEDURE dbo.Update<%=SourceTable.Name %>
第二步为存储过程创造将要声明的参数列表
//开始循环遍历每列
//开始循环遍历每列 <% for (int i = 0; i < SourceTable.Columns.Count; i++) { %> //传递每列给GetSqlParameterStatement函数 <%= GetSqlParameterStatement(SourceTable.Columns[i]) %> //循环结束条件 <% if (i < SourceTable.Columns.Count - 1) { %>,<% } %> <% } % > AS
定义GetSqlParameterStatement方法接受列参数返回参数名，和字段类型，注意函数要放在
<script runat="template"></script> 里
<script runat="template"> public string GetSqlParameterStatement(ColumnSchema column) { string param = "@" + column.Name + " " + column.NativeType; switch (column.DataType) { case DbType.Decimal: { param += "(" + column.Precision + ", " + column.Scale + ")"; break; } default: { if (column.Size > 0) { param += "(" + column.Size + ")"; } break; } } return param; } </script>
接下来创建存储过程的Update 部分，语法类似不再说明
UPDATE [<%= SourceTable.Name %>] SET
<% for (int i = 0; i < SourceTable.NonPrimaryKeyColumns.Count; i++) { %>
[<%= SourceTable.NonPrimaryKeyColumns[i].Name %>] = @<%= SourceTable.NonPrimaryKeyColumns[i].Name %><% if (i < SourceTable.NonPrimaryKeyColumns.Count - 1) { %>,<% } %>
<% } %>
//where条件，注意主键提取方法
WHERE
<% for (int i = 0; i < SourceTable.PrimaryKey.MemberColumns.Count; i++) { %>
<% if (i > 0) { %>AND <% } %>
[<%= SourceTable.PrimaryKey.MemberColumns[i].Name %>] = @<%= SourceTable.PrimaryKey.MemberColumns[i].Name %>
<% } %>最终为模板为如下形式
<%@ CodeTemplate Language="C#" TargetLanguage="T-SQL" Description="Generates a update stored procedure." %> <%@ Property Name="SourceTable" Type="SchemaExplorer.TableSchema" Category="Context" Description="Table that the stored procedures should be based on." %> <%@ Assembly Name="SchemaExplorer" %> <%@ Import Namespace="SchemaExplorer" %> <script runat="template"> public string GetSqlParameterStatement(ColumnSchema column) { string param = "@" + column.Name + " " + column.NativeType; switch (column.DataType) { case DbType.Decimal: { param += "(" + column.Precision + ", " + column.Scale + ")"; break; } default: { if (column.Size > 0) { param += "(" + column.Size + ")"; } break; } } return param; } </script> CREATE PROCEDURE dbo.Update<%= SourceTable.Name %> <% for (int i = 0; i < SourceTable.Columns.Count; i++) { %> <%= GetSqlParameterStatement(SourceTable.Columns[i]) %><% if (i < SourceTable.Columns.Count - 1) { %>,<% } %> <% } %> AS UPDATE [<%= SourceTable.Name %>] SET <% for (int i = 0; i < SourceTable.NonPrimaryKeyColumns.Count; i++) { %> [<%= SourceTable.NonPrimaryKeyColumns[i].Name %>] = @<%= SourceTable.NonPrimaryKeyColumns[i].Name %><% if (i < SourceTable.NonPrimaryKeyColumns.Count - 1) { %>,<% } %> <% } %> WHERE <% for (int i = 0; i < SourceTable.PrimaryKey.MemberColumns.Count; i++) { %> <% if (i > 0) { %>AND <% } %> [<%= SourceTable.PrimaryKey.MemberColumns[i].Name %>] = @<%= SourceTable.PrimaryKey.MemberColumns[i].Name %> <% } %>
将其用CodeSmith Explorer.exe打开
可以任意选择数据库中的表,这里选择NorthWind中的0rders表
然后生成代码，就创建好了存储过程
CREATE PROCEDURE dbo.UpdateOrders
@OrderID int,
@CustomerID nchar(5),
@EmployeeID int,
@OrderDate datetime,
@RequiredDate datetime,
@ShippedDate datetime,
@ShipVia int,
@Freight money,
@ShipName nvarchar(40),
@ShipAddress nvarchar(60),
@ShipCity nvarchar(15),
@ShipRegion nvarchar(15),
@ShipPostalCode nvarchar(10),
@ShipCountry nvarchar(15)
AS
UPDATE [Orders] SET
[CustomerID] = @CustomerID,
[EmployeeID] = @EmployeeID,
[OrderDate] = @OrderDate,
[RequiredDate] = @RequiredDate,
[ShippedDate] = @ShippedDate,
[ShipVia] = @ShipVia,
[Freight] = @Freight,
[ShipName] = @ShipName,
[ShipAddress] = @ShipAddress,
[ShipCity] = @ShipCity,
[ShipRegion] = @ShipRegion,
[ShipPostalCode] = @ShipPostalCode,
[ShipCountry] = @ShipCountry
WHERE
[OrderID] = @OrderID同样，我们可以选择其他的表创建 Updata存储过程，也可以自定义其他诸如insert delete等的存储过程，是不是很方便？^-^
以上只是CodeSmith的简单应用，还有其他的功能有待大家探索了。
关于CodeSmith社区一些模板资源，大家可以去如下地址选择下载
CodeSmith Peer Support Forum
Codesmith templates library