Question

I execute SQL scripts to change the database schema. It looks something like this:

using (var command = connection.CreateCommand())
{
    command.CommandText = script;
    command.ExecuteNonQuery();
}

Additionally, the commands are executed within a transaction.

The scrip looks like this:

Alter Table [TableName]
ADD [NewColumn] bigint NULL

Update [TableName]
SET [NewColumn] = (SELECT somevalue FROM anothertable)

I get an error, because NewColumn does not exist. It seems to parse and validate it before it is executed.

When I execute the whole stuff in the Management Studio, I can put GO between the statements, then it works. When I put GO into the script, ADO.NET complains (Incorrect syntax near ‘GO’).

I could split the script into separate scripts and execute it in separate commands, this would be hard to handle. I could split it on every GO, parsing the script myself. I just think that there should be a better solution and that I didn’t understand something. How should scripts like this be executed?

---

My implementation if anyone is interested in, according to John Saunders’ answer:

List<string> lines = new List<string>();
while (!textStreamReader.EndOfStream)
{
    string line = textStreamReader.ReadLine();
    if (line.Trim().ToLower() == "go" || textStreamReader.EndOfStream)
    {
        ExecuteCommand(
            string.Join(Environment.NewLine, lines.ToArray()));

        lines.Clear();
    }
    else
    {
        lines.Add(line);
    }
}

Answer 1

You have to run each batch separately. In particular, to run a script that may contain multiple batches (“GO” keywords), you have to split the script on the “GO” keywords.

Not Tested:

string script = File.ReadAllText("script.sql");
string[] batches = script.Split(new [] {"GO"+Environment.NewLine}, StringSplitOptions.None);
foreach (string batch in batches)
{
    // run ExecuteNonQuery on the batch
}