title: how to remove duplicate values of two different tables with only two columns in common?
body: <p>I have two tables with only  two columns in common that I want to compare to each other and remove duplicate of the common columns</p>
  <p>for example TABLE A has 4 columns and table B has 6 columns , I want to get the records of table A , BUT  without the records where the rows matches ( when the values of the two common columns matches )</p>
  <p>for example in the common two columns in  tabe A there is code=x , Nature =y and in table B there is also code=x , Nature =y , so this record should be removed when I fetch the table A records ...  I'm using visual studio c# and I didn't know what query to do to fetch these recrods ,any help please</p>