title: Without getting duplicate values merge multiple databases with same schema
body: <p>I have two instances and each has 300 Databases, I want to merge all this databases in one Database without getting any duplicate rows. All Databases have same schema.</p>
  
  <p>How can I solve this problem only using T-SQL, don't want to use any tools.</p>
  
  <p>I am using SQL Server 2012.</p>