SSIS ->> Script Task

 利用Script Task，咱們能夠作一些自己SSIS沒能知足咱們的，或者實現起來效果不夠理想的。好比說咱們想作一件這樣的事情，去檢查某個文件是否爲空。若是咱們經過Row Count組件來實現，性能上不理想，由於我又並不須要要知道究竟文件包含多少行數據。咱們只須要簡單地知道文件是否包含數據。咱們能夠經過寫C#代碼，去調用BinaryStream的方法來讀取該文件的前幾行就能夠肯定是否文件包含數據。總的來講，Script Task能作事情分幾類：1） 讀取和改變包的變量；2）讀取包的屬性；3）用C#或者VS代碼實現業務邏輯，作有一些驗證檢查工做；4）控制workflow的執行；

 

上面說到的那個檢查數據文件是否爲空的例子，咱們能夠把這樣的C#代碼放到一個統一的項目中，而後編譯生成DLL庫（Assembly），再加載到Script Task裏面（或者說被引用），這樣能夠減小代碼的重複。

 

Script Task中的DTS對象實際上是對Microsoft.SqlServer.Dts.Tasks.ScriptTask.ScriptObjectModel的實例化。它包含了一下的成員：

1) Connections：能夠引用Package的Connection Managers
2) Events：能夠引用Package的Events

3) ExecutionValue：

4) TaskResult：能夠用來手動指定成功（success）或者失敗（failure）

5) Transaction

6) VariableDispenser：能夠用來獲取包的Variables

7) Variables：能夠用來存儲Varibales

8) Log：寫log

 

引用SSIS包的變量： Dts.Variables[「User::SomeStringVariable」].Value = 「MyValue」;

改變包的變量Dts.Variables[「User::HappyPathEnum」].Value = 1;

改變TaskResult屬性來告訴SSIS的包當前組件任務的執行是成功仍是失敗了，從而影響後面整個workflow的執行

Dts.TaskResult = (int)ScriptResults.Success;

VariableDispenser提供了鎖定變量的方法能夠防止在解除鎖定該變量被改變

Dts.VariableDispenser.LockForRead("SomeVariable")

 

Dts.VariableDispenser.GetVariables(vars)能夠把當前包的variables賦給某個variables集合

嘗試從Variables集合中讀取沒有賦制值的變量將會拋出異常

 

Script Task對變量是大小寫敏感的，必須把要再script代碼中用到變量設置到ReadOnlyVariables或ReadWriteVariables

 

下面是一個Script Task鏈接DataSource的例子：

public void Main()
{
string myPackageId = Dts.Variables[「System::PackageID」].Value.ToString();
string myValue = string.Empty;
string cmdString = 「SELECT VALUE FROM SSIS_SETTING 「 +
「WHERE PACKAGE_ID= @PACKAGEID And SETTING= @SETTINGID」;
try
{
SqlConnection mySqlConn =
(SqlConnection)Dts.Connections[0].AcquireConnection(null);
mySqlConn = new SqlConnection(mySqlConn.ConnectionString);
mySqlConn.Open();
SqlCommand cmd = new SqlCommand();
cmd.CommandText = cmdString;
SqlParameter parm = new SqlParameter(「@PACKAGEID」, SqlDbType.UniqueIdentifier);
parm.Value = new Guid(myPackageId);
cmd.Parameters.Add(parm); parm = new SqlParameter(「@SETTINGID」,
SqlDbType.NVarChar);
parm.Value = 「LOGFILEPATH」;
cmd.Parameters.Add(parm);
cmd.Connection = mySqlConn;
cmd.CommandText = cmdString;
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
myValue = reader[「value」].ToString();
}
Dts.Variables[「User::LOGFILEPATH」].Value = myValue;
reader.Close();
mySqlConn.Close();
mySqlConn.Dispose();
}
catch
{
Dts.TaskResult = (int)ScriptResults.Failure;
throw;
}
System.Windows.Forms.MessageBox.Show(myValue);
Dts.TaskResult = (int)ScriptResults.Success;
}

下面是Script Task從FTP Server拿數據的例子：
ConnectionManager conn = default(ConnectionManager);
FtpClientConnection ftp = default(FtpClientConnection);
string[] folderNames = null;
string[] fileNames = null;
ArrayList fileArray = new ArrayList();
conn = Dts.Connections(「FTPServer」);
ftp = new FtpClientConnection(conn.AcquireConnection(null));
ftp.Connect();
ftp.GetListing(folderNames, fileNames);
foreach (string s in fileNames) {
fileArray.Add(s);
}
Dts.Variables(「FileList」).Value = fileArray;
ftp.Close();
Dts.TaskResult = ScriptResults.Success;

下面是Script Task寫入數據到XML文件的例子：
public void Main()
{
SqlConnection sqlConn;
string cmdString = 「SELECT * FROM SSIS_SETTING 「;
try
{
sqlConn = (SqlConnection)(Dts.Connections[「AdventureWorks」])
.AcquireConnection(Dts.Transaction
);
sqlConn = new SqlConnection(sqlConn.ConnectionString);
sqlConn.Open();
SqlCommand cmd = new SqlCommand(cmdString, sqlConn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ds.WriteXml(new System.IO.StreamWriter
(「C:\\ProSSIS\\Files\\myPackageSettings.xml」));
sqlConn.Close();
}
catch
{
Dts.TaskResult = (int)ScriptResults.Failure;
throw;
}
Dts.TaskResult = (int)ScriptResults.Success;
}

下面是Script Task序列化數據再寫入到XML文件的例子：
public void Main()
{
SqlConnection sqlConn;
string cmdString = 「SELECT * FROM SSIS_SETTING 「;
try
{
sqlConn = (SqlConnection)(Dts.Connections[「AdventureWorks」])
.AcquireConnection(Dts.Transaction
);
sqlConn = new SqlConnection(sqlConn.ConnectionString);
sqlConn.Open();
SqlCommand cmd = new SqlCommand(cmdString, sqlConn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ds.WriteXml(new System.IO.StreamWriter
(「C:\\ProSSIS\\Files\\myPackageSettings.xml」));
sqlConn.Close();
}
catch
{
Dts.TaskResult = (int)ScriptResults.Failure;
throw;
}
Dts.TaskResult = (int)ScriptResults.Success;
}

用XMLSerializer類來序列化XML數據
[Serializable()]
public class SSISSetting
{
public string PackageId { get; set; }
public string Setting { get; set; }
public string Value { get; set; }
}

public void Main()
{
SqlConnection sqlConn;
string cmdString = 「SELECT * FROM SSIS_SETTING 「;
try
{
sqlConn = (SqlConnection)(Dts.Connections[「AdventureWorks」])
.AcquireConnection(Dts.Transaction);
sqlConn = new SqlConnection(sqlConn.ConnectionString);
sqlConn.Open();
SqlCommand cmd = new SqlCommand(cmdString, sqlConn);
SqlDataReader dR = cmd.ExecuteReader();
List<SSISSetting> arrayListSettings = new List<SSISSetting>();
while (dR.Read())
{
SSISSetting oSet = new SSISSetting();
oSet.PackageId = dR[「PACKAGE_ID」].ToString();
oSet.Setting = dR[「SETTING」].ToString();
oSet.Value = dR[「VALUE」].ToString();
arrayListSettings.Add(oSet);
}
StreamWriter outfile = new StreamWriter
(「C:\\ProSSIS\\Files\\myObjectXmlSettings.xml」);
XmlSerializer ser = new XmlSerializer(typeof(List<SSISSetting>));
ser.Serialize(outfile, arrayListSettings);
outfile.Close();
outfile.Dispose();
sqlConn.Close();
}
catch
{
Dts.TaskResult = (int)ScriptResults.Failure;
throw;
}
Dts.TaskResult = (int)ScriptResults.Success;
}

 咱們也能夠手工觸發Event Handler

public void Main(){string taskName = Dts.Variables[「System::TaskName」].Value.ToString();bool retVal = false;Dts.Events.FireInformation(0, taskName, String.Format(「Starting Loop Operation at {0} 「,DateTime.Now.ToString(「MM/dd/yyyy hh:mm:ss」)), 「」, 0,ref retVal);for(int i=0; i <= 10; i++){Dts.Events.FireProgress(String.Format(」Loop in iteration {0}」, i),i * 10, 0, 10, taskName, ref retVal);}Dts.Events.FireInformation(0, taskName, String.Format(」Completion Loop Operationat {0} 」, DateTime.Now.ToString(」mm/dd/yyyy hh:mm:ss」)), 」」, 0, ref retVal);Dts.Events.FireWarning(1, taskName, 」This is a warning we want to pay attentionto...」, 」」, 0);Dts.Events.FireWarning(2, taskName, 」This is a warning for debugging only...」,」」, 0);Dts.Events.FireError(0, taskName, 」If we had an error it would be here」, 」」, 0);}