Something to try if Squirrel SQL stops working on Windows

I’ve been using the free Squirrel SQL SQL client under windows for a month or so now.  It’s a good tool, though somewhat annoying to get working.  Today it stopped working.  The loading splash screen would display, the progress bar would get about halfway through and then Squirrel would exit without any messages.  I had no desire to recreate all of my connections or reinstall the various drivers again, so I really wanted to fix my installation.

After trolling through forums, there was a suggestion that the problem may have been preferences related. No precise solution was offered, but I began to experiment to see if this was my problem.

First, I found the preferences folder, which lives in Windows’ documents and settings folder (eg. c:\Documents and Settings\). Inside this folder will be Squirrel’s preferences folder, named ‘.squirrel-sql’. I renamed this and restarted Squirrel. Things looked good with the application starting, so it seemed I was looking in the right place. In order to troubleshoot further, I wanted to restore the state of the application, so I renamed the new preferences folder that Squirrel had created and tried to rename the old preferences folder.

No luck! Windows didn’t like me trying to rename the folder back to its original name. I ran Squirrel again, which caused Squirrel to create another preferences folder. I now had three folders – squirrel-sql.old, squirrel-sql.new and the current preferences folder ‘.squirrel-sql’. I opened the old preferences folder, copied the contents and pasted them into the ‘.squirrel-sql’ folder.

Looking inside the preferences folder, I could two folders ‘plugins’, and ‘logs’. I could also see a number of xml files. Now that I had found the broad area I needed to investigate, I wanted to only change one element at a time. As my main objective in resurrecting Squirrel was to not lose my database connections and plugins, I ignored the xml files that were related to these, and looked at the most interestingly named file – ‘prefs.xml’. I renamed this to ‘prefs.xml.bak’ and restarted Squirrel. Still no joy, so I closed Squirrel and restored the original name of the file..

I repeated this step for ‘sql_history.xml’, thinking that this file might be dynamic enough to cause problems. Again, Squirrel failed to start correctly.

Next, was a file named SQLAliases23_treeStructure.xml. Suspiciously, this was zero bytes, which seemed odd for something that looked like it was supposed to contain some kind of data structure. I added a ‘.bak’ extension to this and restarted Squirrel again.

Success! I closed Squrrel and I could see that it had recreated the SQLAliases treeStructure file again, this time with data. I restarted Squirrel one more time to make sure that there wasn’t some recurring problem with my database aliases, and it happily started again with my connections and query history intact.