if VarIsNull(ADOQuery2.Fields[3].Value) then
begin
TCZCBH:=0
end
else
begin
TCZCBH:=ADOQuery2.Fields[3].Value;
end;
为什么我用上面的句子,即使字段为空,仍不能给让TCZCBH等于0呢?谢谢
var
LkResult:Variant; //查找字段结果
begin
qryStudent.Open; //打开数据集
LkResult:=qryStudent.Lookup('xh',trim(cbNo.Text),'xm');
if not (VarType(LkResult) in [varNull]) then //字段为空的操作
begin
cbName.Text:=LkResult;
cbName.Enabled:=False;
end
else begin //字段不为空的操作
cbName.Text:='';
cbName.Enabled:=True;
end;
qryStudent.Close;
end;