Article ID: 319243 - View products that this article applies to.
This article was previously published under Q319243
When you use an ANSI ODBC driver, the ODBC Driver Manager may incorrectly return SQL_NO_DATA_FOUND for a column that is defined as VARCHAR or CHAR and that has an empty string in it. The problem does not occur if the column contains some data or a "NULL" value. The problem only occurs if the data is an empty string and you bind it from the client side with SQL_C_WCHAR.
The ODBC Driver Manager incorrectly assumes that the driver does not have any data when it tries to convert the empty string from ANSI to UNICODE.
To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/290211/EN-US/ )INF: How to Obtain the Latest SQL Server 2000 Service Pack
A simple workaround for this problem is to bind the column as SQL_C_CHAR instead of SQL_C_WCHAR.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Microsoft SQL Server 2000 Service Pack 3.
Legacy applications that use an ANSI ODBC driver may not experience this problem, because they may not bind the column as SQL_C_WCHAR. Because the Microsoft ODBC .NET Provider binds character columns as SQL_C_WCHAR by default, you may experience this problem if you use the Microsoft ODBC .NET Provider with an ANSI driver. Note that the Microsoft ODBC .NET Provider returns "NO_DATA" when this problem occurs.
Steps to Reproduce BehaviorThe following native sample demonstrates the problem: