我需要确定创建的表中是否有条目。
我需要的是,
if (TableIsEmpty) then
do_something
else
do_something_else;
我写这篇文章的目的是:
Function IsTableEmpty:Boolean;
Var
DataSource : string;
Begin
DataSource :=
'Provider=Microsoft.Jet.OLEDB.4.0'+
';Data Source=c:\mydb.mdb'+
';Persist Security Info=False';
Form2.ADOConnection1.ConnectionString := DataSource;
Form2.ADOConnection1.LoginPrompt := False;
Form2.ADOCommand1.Connection := Form2.ADOConnection1;
Form2.ADOTable1.ConnectionString := DataSource;
Form2.ADOTable1.Connection := Form2.ADOConnection1;
if (Form2.ADOTable1.IsEmpty)then
result := true
else
result := false;
End;
但是不管表的状态如何,这个函数都返回true!
编辑***
修改代码:
Function IsTableEmpty:Boolean;
Var
DataSource, cs : string;
Begin
DataSource :=
'Provider=Microsoft.Jet.OLEDB.4.0'+
';Data Source=c:\Users.mdb'+
';Persist Security Info=False';
Form2.ADOConnection1.ConnectionString := DataSource;
Form2.ADOConnection1.LoginPrompt := False;
Form2.ADOCommand1.Connection := Form2.ADOConnection1;
Form2.ADOTable1.Connection := Form2.ADOConnection1;
Form2.ADOTable1.TableName := 'userIdentification';
Form2.ADOTable1.Active := True;
cs := 'Select * from userIdentification';
Form2.ADOCommand1.CommandText := cs;
Form2.ADOCommand1.Execute;
if Form2.ADOTable1.RecordCount <= 0 then
result := true
else
result := false;
Form2.ADOConnection1.Close;
End;
此函数始终返回false!啊!
最佳答案
if Form2.ADOTable1.RecordCount =< 0 then
do_something
else
do_something_else;
在成功执行select语句后运行