Script component 用法
在SSIS中，可以使用C#编写脚本，这是十分激动人心的事，能够使用C#代码，使得Script Component无所不能。
第一部分：组件简介
Script Component 有三种类型：Source, Destination and Transformation
1，每种类型的脚本，都有两种类型的参数：ReadOnly 和ReadWrite，在脚本中可以使用 this.Variables.VariableName 来获取或设置参数变量的值
示例：创建四个Variable，并传递给Script component
SSIS十分友好，在脚本中自动生成了一个子类，将Variable Name作为属性添加到子类中，引用Variable Name十分简单
public class ScriptMain : UserComponent
在脚本代码中，使用 this.Variables.VariableName 来获取或设置参数变量的值
2，可以为 Script component 指定connection ，如果在脚本中使用Ado.net，可以直接创建Ado.net connection manager，在脚本中，使用以下代码来引用connection
IDTSConnectionManager100 cnManager = this.Connections.Connection;
3，Script component 不仅有输入的Variable，而且还有output / input columns，设置output / input columns 以便输出或输入表数据
示例中增加两列Code和name，分别是string类型
第二部分：Source 组件示例
4，如果Script Component 作为Source，那么使用脚本获取数据之后，可以使用将数据逐行添加到Source 的输出buff中。
在将获得的数据集插入到output buff中时，SSIS使用的代码逻辑是：先向output buff中插入一行，然后为该行的字段赋值
DataRow dr=dt.Rows[0];
this.Output0Buffer.AddRow();
this.Output0Buffer.Code = dr["code"].ToString();
this.Output0Buffer.Name = dr["name"].ToString();
示例Code
DataTable dt;
IDTSConnectionManager100 cnManager;
SqlConnection cnn;
/// <summary>
/// This method is called once, before rows begin to be processed in the data flow.
///
/// You can remove this method if you don't need to do anything here.
/// </summary>
public override void PreExecute()
{
base.PreExecute();
cnManager = this.Connections.Connection;
cnn = (SqlConnection)cnManager.AcquireConnection(null);
SqlCommand cmd = cnn.CreateCommand();
cmd.CommandText = "select code,name from [dbo].[tbExcel]";
cmd.CommandType = CommandType.Text;
cmd.CommandTimeout = 60000;
dt = new DataTable("dt");
SqlDataAdapter sda = new SqlDataAdapter(cmd);
sda.Fill(dt);
}
/// <summary>
/// This method is called after all the rows have passed through this component.
///
/// You can delete this method if you don't need to do anything here.
/// </summary>
public override void PostExecute()
{
base.PostExecute();
cnManager.ReleaseConnection(cnn);
}
public override void CreateNewOutputRows()
{
foreach (DataRow dr in dt.Rows)
{
this.Output0Buffer.AddRow();
this.Output0Buffer.Code = dr["code"].ToString();
this.Output0Buffer.Name = dr["name"].ToString();
}
}
5，Script Component做为Destination，既然是作为Destination，那么肯定是有input column，用以接收上个数据源组件或转换组件的输出数据流。
示例代码如下
SqlCommand cmd = new SqlCommand();
DataTable dt = new DataTable("dt");
IDTSConnectionManager100 cnManager;
SqlConnection cnn;
/// <summary>
/// This method is called once, before rows begin to be processed in the data flow.
///
/// You can remove this method if you don't need to do anything here.
/// </summary>
public override void PreExecute()
{
base.PreExecute();
cnManager = this.Connections.Connection;
cnn = (SqlConnection)cnManager.AcquireConnection(null);
cmd.Connection = cnn;
cmd.CommandType = CommandType.Text;
cmd.CommandTimeout = 60000;
dt.Columns.Add("code", typeof(string));
dt.Columns.Add("name", typeof(string));
}
/// <summary>
/// This method is called after all the rows have passed through this component.
///
/// You can delete this method if you don't need to do anything here.
/// </summary>
public override void PostExecute()
{
base.PostExecute();
foreach(DataRow dr in dt.Rows)
{
string strSql = string.Format(@"
insert into dbo.tbExcel2(code,name)
values('{0}','{1}')"
, dr["code"].ToString(), dr["name"].ToString());
cmd.CommandText = strSql;
cmd.ExecuteNonQuery();
}
cnManager.ReleaseConnection(cnn);
}
/// <summary>
/// This method is called once for every row that passes through the component from Input0.
///
/// Example of reading a value from a column in the the row:
/// string zipCode = Row.ZipCode
///
/// Example of writing a value to a column in the row:
/// Row.ZipCode = zipCode
/// </summary>
/// <param name="Row">The row that is currently passing through the component</param>
public override void Input0_ProcessInputRow(Input0Buffer Row)
{
DataRow dr = dt.NewRow();
dr["code"] = Row.code;
dr["name"] = Row.name;
dt.Rows.Add(dr);
}
6，Script Component 作为 Transformation ，转换，顾名思义是将输入进行转换成符合要求的输出，所以，作为 Transformation 的Script Component 既有input columns，也有output columns。
示例代码如下，Input0Buffer 这个类中即包含了InputColumns，也包含了OutputColumns，InputColumns的Column是ReadOnly的，通过Input0Buffer 实例对OutputColumns进行赋值，转换数据流。
/// <summary>
/// This method is called once, before rows begin to be processed in the data flow.
///
/// You can remove this method if you don't need to do anything here.
/// </summary>
public override void PreExecute()
{
base.PreExecute();
/*
* Add your code here
*/
}
/// <summary>
/// This method is called after all the rows have passed through this component.
///
/// You can delete this method if you don't need to do anything here.
/// </summary>
public override void PostExecute()
{
base.PostExecute();
/*
* Add your code here
*/
}
/// <summary>
/// This method is called once for every row that passes through the component from Input0.
///
/// Example of reading a value from a column in the the row:
/// string zipCode = Row.ZipCode
///
/// Example of writing a value to a column in the row:
/// Row.ZipCode = zipCode
/// </summary>
/// <param name="Row">The row that is currently passing through the component</param>
public override void Input0_ProcessInputRow(Input0Buffer Row)
{
Row.codeout = Row.code + "_out";
Row.nameout = Row.name + "_out";
}
