当字段有为空时,就出错,提示不可把NULL赋给STRING类型,这要怎么办啊? with adoquery1 do begin close; sql.Clear; try sql.add('select *from 通信录 where 所属用户=:yuanhu and 姓名=:xinmin'); adoquery1.Parameters.parambyname('yuanhu').value:=label2.caption; adoquery1.Parameters.parambyname('xinmin').value:=edit19.text; adoquery1.Open; if adoquery1.recordcount=0 then begin showmessage('此人不存在,请检查!'); edit19.text:=''; edit20.Text:=''; edit21.Text:=''; edit22.Text:=''; edit23.Text:=''; edit24.Text:=''; edit25.Text:=''; edit26.Text:=''; edit27.Text:=''; edit19.setfocus end else begin
null当然不能赋给string类型了,赋值之前先做判断: if NOT adoquery1.fields[3].IsNull then edit20.text:=adoquery1.fields[3].Value;
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