Developer notes: Null value for ADO command parameter

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Источник: http://axdevnotes.blogspot.com/2008/...parameter.html
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Now I whith my colleagues work on integration Axapta with the other business application named M&F (Management and Finance). Our company uses M&F for more than eight years and now it is time for new ERP system. This application has 2-tier architecture, and its business logic is on the server side. We use stored procedure API for document exchange from Axapta to M&F. Some days ago I tried to call stored procedure on MS SQL Server from X++. For several parameters it was necessary to set null value. At first I instantiated COMVariant like this:

COM parameter = new COM("ADODB.Parameter");
COMVariant nullParam = new COMVarian(ComVariantInOut::In, ComVariantType::VT_NULL);
;
parameter.name("@paramName");
parameter.type(#adInteger);
parameter.value(nullParam); // This method throw exception!

After several hours research I found decision of this problem:

COM parameter = new COM("ADODB.Parameter");
nullParam = new COMVariant();
;
parameter.name("@paramName");
parameter.type(#adInteger);
nullParam.variantType(ComVariantType::VT_NULL);
parameter.value(nullParam); // This method doesn`t throw exception now!

I think problem is in constructor of the COMVariant class. What is your opinion?


Источник: http://axdevnotes.blogspot.com/2008/...parameter.html