Good question. It made me look up the documentation. The answer is a definite "sometimes". I have always used the OleDb client, so I have only experienced the qmark. I quote from the Microsoft documentation........ V V V V V V V V V V V V V V V V V V V V V
The syntax for parameter placeholders depends on the data source. The .NET Framework data providers handle naming and specifying parameters and parameter placeholders differently. This syntax is customized to a specific data source, as described in the following table. Data provider Parameter naming syntax System.Data.SqlClient<http://msdn.microsoft.com/en-us/library/system.data.sqlclient%28lightweight%29.aspx> Uses named parameters in the format @parametername. System.Data.OleDb<http://msdn.microsoft.com/en-us/library/system.data.oledb%28lightweight%29.aspx> Uses positional parameter markers indicated by a question mark (?). System.Data.Odbc<http://msdn.microsoft.com/en-us/library/system.data.odbc%28lightweight%29.aspx> Uses positional parameter markers indicated by a question mark (?). System.Data.OracleClient<http://msdn.microsoft.com/en-us/library/system.data.oracleclient%28lightweight%29.aspx> Uses named parameters in the format :parmname (or parmname).I ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ So it would appear that if I always use the OleDb provider, then I always have qmark parameter style, even if I am opening an Oracle data base. The conversion from pyformat to qmark would be done programatically in adodbapi. There may still be a problem with differences in dialect between different SQL engines. I think many of those are coded in to the various database front ends, so that an "interchangable" adapter would still need to know what engine it is using and make some changes to adapt itself. For example, do you use "TOP" or "LIMIT" to restrict the number of rows requested? MS-SQL uses "TOP" while MySQL uses "LIMIT", both through the OleDb provider. I definitely do not want to be restricted to only MS-SQL from IronPython/django. The existing django-mssql code is engine specific. I would like to remove that restriction, but do not know (yet) if that is possible. adodbapi itself is engine agnostic. -- Vernon On Fri, Oct 23, 2009 at 2:43 PM, Josh <j...@globalherald.net> wrote: > Vernon Cole wrote: > > "The big thing will be paramstyle format convertion. MS-SQL uses qmark. I > am told that django wants pyformat." > > Quick question. Is this new database driver going to be specific to > MS-SQL, or does the ADO.NET specification specify qmark in place of > Pyformat? > > The reason I ask is it would be really slick to be able to use any > ADO.NETdata source on the back end. It would be even slicker if we could do > this > interchangeably. For example, suppose you have a Django site running under > RHEL + Apache + PostgreSQL. It would be nifty if you could take the same > code, with little or no modification, and run it under IIS + IronPython > against that same PostgreSQL database using one of the PostgreSQL .NET data > providers. > > Cheers, > -Josh > > > _______________________________________________ > Users mailing list > Users@lists.ironpython.com > http://lists.ironpython.com/listinfo.cgi/users-ironpython.com >
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