title: SSIS derived column error
body: <p>I got this error while debugging in SSIS:</p>
  
  <blockquote>
    <blockquote>
      <p>Error: 0xC0049064 at Data Flow Task, Derived Column [70]: An error occurred while attempting to perform a type cast.
      Error: 0xC0209029 at Data Flow Task, Derived Column [70]: SSIS Error Code DTS_E_INDUCEDTRANSFORMFAILUREONERROR. The "component "Derived Column" (70)" failed because error code 0xC0049064 occurred, and the error row disposition on "output column "EVENT_DT" (118)" specifies failure on error. An error occurred on the specified object of the specified component. There may be error messages posted before this with more information about the failure.
      Error: 0xC0047022 at Data Flow Task: SSIS Error Code DTS_E_PROCESSINPUTFAILED. The ProcessInput method on component "Derived Column" (70) failed with error code 0xC0209029. The identified component returned an error from the ProcessInput method. The error is specific to the component, but the error is fatal and will cause the Data Flow task to stop running. There may be error messages posted before this with more information about the failure.
      Error: 0xC0047021 at Data Flow Task: SSIS Error Code DTS_E_THREADFAILED. Thread "WorkThread0" has exited with error code 0xC0209029. There may be error messages posted before this with more information on why the thread has exited.
      Information: 0x40043008 at Data Flow Task, DTS.Pipeline: Post Execute phase is beginning.
      Information: 0x40043009 at Data Flow Task, DTS.Pipeline: Cleanup phase is beginning.
      Information: 0x4004300B at Data Flow Task, DTS.Pipeline: "component "DataReaderDest" (143)" wrote 0 rows.
      Task failed: Data Flow Task
      Warning: 0x80019002 at Package: SSIS Warning Code DTS_W_MAXIMUMERRORCOUNTREACHED. The Execution method succeeded, but the number of errors raised (4) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors.
      SSIS package "Package.dtsx" finished: Failure.</p>
    </blockquote>
  </blockquote>
  
  <p>My expression is: </p>
  
  <pre><code>(DT_DBTIMESTAMP)(SUBSTRING(EVENT_D,7,4) + "-" + 
   SUBSTRING(EVENT_D,4,2) + "-" + 
   SUBSTRING(EVENT_D,1,2) + EVENT_T)
  </code></pre>
  
  <p>My original data are in this sequence:</p>
  
  <pre><code>EVENT_D: DD/MM/YYYY
  EVENT_T: HH:MM:SS
  </code></pre>
  
  <p>Any help are appreciated. I have try changing my expression numerous time but still fails.</p>