System.Data.SqlServerCe.SqlCeCommand Has A Bug Related To SqlCeParameter Order That Causes Exceptions.

I came across a frustrating bug last week. Basically, whenever I tried to execute almost any sql query with unnamed parameters (i.e. using "?" instead of "@param_name" in the SQL text), an exception would be thrown.

After trying lots and lots of things and navigating my way through the internals of System.Data.SqlServerCe.dll, I discovered that the method System.Data.SqlServerCe.SqlCeCommand.CreateParameterAccessor(...) has a bug.

The bug is that the private arrays "parameters" and "metadata" are ordered differently, yet at one point in CreateParameterAccessor(...) they are compared using the same index. Here are the two lines:
p = this.parameters[ i ];
and
MetaData info = metadata[ i ]
and then the column data types of "info" & "p" are incorrectly compared in a later method, ValidateDataConversion(...).

So take a step back... how are they ordered differently? From observation, I concluded the following:
The "parameters" array is ordered exactly in the order that the DbParameter's were added to the DbCommand object.
The "metadata" array is ordered according to the column order of the table in the database.


So what causes the exception? Well, CreateParameterAccessor(...) passes data types from two different columns (one type taken from parameters[ i ] and the other from metadata[ i ]) on to SqlCeType.ValidateDataConversion(...). And, of course, if they differ (e.g. one column is of type DateTime and the other is a SmallInt), an exception is thrown.
I've found two workarounds, and both seem to work well.
The first is to name the SqlCeParameters (e.g. "SELECT ... WHERE id=@id"). This causes the buggy branch of code to be completely bypassed.

The second is to add the SqlCeParameters in the exact same order as the columns exist in the table you are accessing. Note, I do *not* mean the order that you select the columns (e.g. "SELECT column1, column2, ..."). I mean the actual order of the columns in the database.

I've included my setup and a stack trace below to help if it can.

My setup is:
.Net CF 3.5
SqlServer CE 3.5
Visual Studio 2008
Deployed to Pocket PC 2003

Here is the stack trace (note the variables passed to ValidateDataConversion):

System.Data.SqlServerCe.dll!System.Data.SqlServerCe.SqlCeType.ValidateDataConversion(System.Data.SqlDbType expectedType = DateTime, System.Data.SqlDbType actualType = SmallInt) + 0x4a bytes
System.Data.SqlServerCe.dll!System.Data.SqlServerCe.SqlCeCommand.CreateParameterAccessor(System.Data.SqlServerCe.MetaData[] metadata = {System.Data.SqlServerCe.MetaData[34]}) + 0x89 bytes
System.Data.SqlServerCe.dll!System.Data.SqlServerCe.SqlCeCommand.CreateDataBindings() + 0x5e bytes
System.Data.SqlServerCe.dll!System.Data.SqlServerCe.SqlCeCommand.CompileQueryPlan() + 0x16f bytes
System.Data.SqlServerCe.dll!System.Data.SqlServerCe.SqlCeCommand.ExecuteCommand(System.Data.CommandBehavior behavior = Default, string method = "ExecuteNonQuery", System.Data.SqlServerCe.ResultSetOptions options = None) + 0xa7 bytes
System.Data.SqlServerCe.dll!System.Data.SqlServerCe.SqlCeCommand.ExecuteNonQuery() + 0x7 bytes