title: Minimum length constraint on a column
body: <p>I'm trying to implement a minimum length constraint in Oracle.</p>
  
  <p>As I read in <a href="https://stackoverflow.com/questions/4426005/how-can-i-create-a-check-constraint-on-a-varchar-column-in-sql-server-specifying">this</a> answer and multiple other similar questions I tried:</p>
  
  <pre><code>ALTER TABLE my_table 
  ADD CONSTRAINT MY_TABLE_PASSWORD_CK CHECK (DATALENGTH(password) &gt;=4)
  </code></pre>
  
  <p>And I am getting <code>"DATALENGTH": invalid identifier"</code>. I also tried:</p>
  
  <pre><code>( DATALENGTH([password]) &gt;=4 )
  ( LEN([password]) &gt;=4 )
  ( LEN(password) &gt;=4 )
  </code></pre>
  
  <p>What is the current format for this check constraint in Oracle?</p>