title: Adding leading zero if length is not equal to 10 digit using sql
body: <p>I am trying to join 2 tables but my problem is that one of the table has 10 digit number and the other one may have 10 or less digit number.  For this reason, i am loosing some data so i would like to do is check the length first if the length is less than 10 digit then i want to add leading zeros so i can make it 10 digit number.  I want to do this when i am joining this so i am not sure if this is possible.  Here is an example if i i have 251458 in the TABLE_WITHOUT_LEADING_ZERO then i want to change it like this: 0000251458.  Here is what i have so far:</p>
  
  <pre><code>select ACCT_NUM, H.CODE
   FROM TABLE_WITH_LEEDING_ZERO D,  TABLE_WITHOUT_LEADING_ZERO H
   WHERE substring(D.ACCT_NUM from position('.' in D.ACCT_NUM) + 2) = cast (H.CODE as varchar (10))
  </code></pre>
  
  <p>thanks</p>