title: Why does BIDS modify connection managers with values from configuration file?
body: <p>I  have been involved in discussions in this forum about whether SSIS overwrites packages when you modify XML config files. The two posts at the bottom of this posting  disagree with each other, one saying packages do get overwritten, one saying they don’t. I believe that I have the answer but am looking for others thoughts on this – if you modify xml package configurations at design time and run the package through visual studio, when the package is saved, the package code  is actually modified by SSIS to reflect the configurations you have changed. However If you run packages through DTEXEC , or SQL Server Agent the package code is not modifed</p>
  <p>If I have a package in Visual Studio, if I modify the servername in the connectionstring (change server A to Server B) in the  XML configurations, and run the package</p>
  <p>The behavior I expect is fine, it writes the data to the table on the second server
  The behavior I DON’T expect is this. When I pull up the connection manager in the package visual studio, server A has been changed to server B</p>
  <p>SSIS has modified the code in my package.</p>
  <p>This behavior can be very confusing and hast cost me a lot of time on the project I am working on. IMHO  should only override values at run time, not overwrite packages at design time!!</p>
  <p>Do you have any thoughts on this?</p>
  <h3>Post 1 states it does overwrite</h3>
  <p><a href="https://stackoverflow.com/questions/14516847/ssis-xml-configuration-modifies-package-xml-am-i-crazy/14516991#comment20248653_14516991">ssis xml configuration modifies package xml - am i crazy?</a></p>
  <h3>Post 2 states it does not overwrite</h3>
  <p><a href="https://stackoverflow.com/questions/14535873/ssis-xml-configurations-configs-overwrite-packages-does-ssis-change-config-w/14545182?iemail=1#14545182">ssis xml configurations - configs overwrite packages - does ssis change config without you telling it to?</a></p>