Get the parameter prefix in ADO.NET

Question

I want to generate several SQL statements based on a column list using the column names as parameters.

Edit: C#

var columns = new string         


        

Answer 1

There are 2 DbCommandBuilder methods that will help you, GetParameterName and GetParameterPlaceholder. These are protected, so you'll need a little reflection to use them.

Check out my answer to the following question for an implementation (also included in the DbExtensions library):

What are your favorite extension methods for C#? (codeplex.com/extensionoverflow)

Answer 2

I found the answer, but I cannot reproduce how I found it:

http://www.codewrecks.com/blog/index.php/2007/09/06/about-parametermarkerformat/

The DbConnection can provide a schema table that also contains the correct format strings for creating command parameter names, except for SqlClient!!

DbProviderFactory myFactory = DbProviderFactories.GetFactory(myProviderName);

using (DbConnection myConnection = myFactory.CreateConnection())
{
    myConnection.ConnectionString = mySettings.ConnectionString;
    myConnection.Open();

    string parameterMarker = myConnection
        .GetSchema(DbMetaDataCollectionNames.DataSourceInformation)
        .Rows[0][DbMetaDataColumnNames.ParameterMarkerFormat].ToString();

    myConnection.Close();
}

For SqlCclient parameterMarker is {0} but should be @{0}. I'll investigate a bit more to find out what is contained in the other schema table columns.