关于数据库字段修改
数据库是SQL SERVER 2008,有一个字段Status类型是vachar,目标是将该字段改写为"NULL"(不能是字符串NULL,必须是NULL型的空字段)
下边的代码高人指点下,Status赋值成什么类型呢?

C/C++ code

TADOQuery *qy=new TADOQuery(this);qy->ConnectionString=ok;qy->SQL->Clear();qy->SQL->Add("SELECT * FROM test WHERE ID = '"+Edit1->Text+"'");qy->Open();qy->Edit();qy->FieldByName("Number")->AsString=suiEdit2->Text;//修改号码qy->FieldByName("Content")->AsString=suiEdit3->Text;//修改内容qy->FieldByName("Status")->AsString=NULL;//修改重发标志qy->Post();

执行后,Status字段内容变为"0",目标是要变为"NULL"

[解决办法]
TADOQuery *qy=new TADOQuery(this);
qy->ConnectionString=ok;
qy->SQL->Clear();
qy->SQL->Add("SELECT * FROM test WHERE ID = '"+Edit1->Text+"'");
qy->Open();
qy->Edit();
qy->FieldByName("Number")->AsString=suiEdit2->Text;//修改号码
qy->FieldByName("Content")->AsString=suiEdit3->Text;//修改内容
qy->FieldByName("Status")->Clear();
qy->Post();