what's "non-blob required in table to perform this operation"（狼来了，救我！)

[capfdipoe]

下面这段程序运行时总出现错误"non-blob required in table to perform this operation"
A->RequestLive=true;
A->Close();
A->SQL->Clear();
A->SQL->Add("select * from sendinformation");
A->Open();
A->Append();
A->FieldValues["S_no"]=frmManage->S_User_no;
A->FieldValues["R_no"]=R_User_no;
A->FieldValues["Letter"]=RichEdit1->Lines->Text;
A->FieldValues["S_time"]=Now();
dmManage->Database1->StartTransaction();
try{
A->ApplyUpdates();
dmManage->Database1->Commit();
}
catch(...){
dmManage->Database1->Rollback();
throw;
}
A->CommitUpdates();

请各位帮我看一看有什么问题，如何解决?

[capfdipoe]

人呢？

[whitelion]

A是query吗，
不能append

[capfdipoe]

#define A dmManage->qrySendInformation
A是query
sorry,忘了告诉你了。