Question

I need to run a sql script that is in a file from my c# application.
The problem is that it creates objects an executes commands on different databases.

In the script, every time i need to change the current database it uses the command

USE [databasename]

and since there are many object creations it uses the command GO a lot of times, so I read the file until i find a GO command and run the sentence in the database; so far so good, but after the command runs the connection returns to the default database (master in this case) ignoring the last USE sentence.

This is the code I use to read the file and execute the script.

using (StreamReader reader = new StreamReader(databaseScriptFile))
  {
      DatabaseFactory.CreateDatabase()
      Database db = new SqlDatabase(connectionstring);
      txbuilder = new StringBuilder();
      bool lastExecute = true;               
      while (!reader.EndOfStream)
      {
          text = reader.ReadLine();
          if (text.Trim().ToUpper() != "GO")
          {
              lastExecute = false;
              txbuilder.AppendLine(text);
          }
          else
          {
              lastExecute = true;
              db.ExecuteNonQuery(CommandType.Text, txbuilder.ToString());
              txbuilder.Length = 0;
          }
      }
      //Make sure that the last sentence is executed
      if (!lastExecute)
          db.ExecuteNonQuery(CommandType.Text, txbuilder.ToString());
  }

It seems that it clears the connection after each ExecuteNonQuery command executing sp_reset_conection (that’s what I get in the profiler)

Is there any elegant and simple way to acomplish this?

Thanks

Answer 1

There’s a good investigation by Joshua Flanagan with test harness and results on his blog. It reads as if he was having a similar problem to what you describe.

There’s two ways to do it, and you’ll have to evaluate which is the best for you, and whether either have any knock-on effects.

1. Explictly open and close the database connection. So rather than just open the database with SqlDatabase, you’ll need to create a SqlConnection and call Open() on it.
2. Simply add Connection Reset=False onto your connection string. I don’t know the pros and cons of this approach however, so don’t know if there’s any side-effects of this as I understand this can disable connection pooling. You’ll know better than I will within the context of your application/utility.

I suggest reading the blog article for all the gory details, then do a little bit of digging around to see which is the best for you.