title: How do I replace missing values in flat file with a NULL mark of appropriate data type?
body: <p>I have a flat file with currency values. Some have values and some don't. So when I am importing data directly through SSIS, if there is no value in row, it is inserting <strong><code>0</code></strong> but technically there is no value. How can I replace these <strong><code>0</code></strong> value using derived column.</p>
  
  <p>I tried the below expressions but both these expressions do not yield the expected results. </p>
  
  <h3>Expression 1:</h3>
  
  <pre><code>MontlyAmt == "" ? NULL(DT_CY) 
  </code></pre>
  
  <h3>Expression 2:</h3>
  
  <pre><code>MontlyAmt == "" ? NULL(DT_CY) : MonthlyAmt
  </code></pre>
  
  <p>How do I import the missing currency data from flat file into database using an SSIS expression?</p>