With Table1 do
Begin
First;
While not EOF do
Begin
{- }
Next;
end;
end;
repeatuntil :
With Table1 do
Begin
First;
Repeat
{- }
until not FindNext;
end;
Locate
Locate , , , . True. , False .
function Locate(const KeyFields: String; const KeyValues: Variant; Options: TLocaleOptions):Boolean
KeyFields , . . KeyValues , i-e KeyValues i- KeyFields. Options , .
IoCaseInsensitivite .
IoPartialKey , ; , "" "", "-", "" ..
Locate - . () - , Locate , .
:
- TDateTimePicker
- OnChange
if DataModule2.Nakls.Locate("NDate", DateTimePicker.Date, []) then
DBGrid1.SetFocus;
Nakls
Lookup
Lookup , , , . . Locate Lookup .
function (const KeyFields: String; const KeyValues: Variant; ResultFields: String): Variant
KeyFields , ( , ). KeyValues , KeyFields. ResultFields , . Variant .
|
|
|
, i- KeyFields i-e KeyValues. , KeyValues ; VarArrayOf.
Locate, - , . , Lookup Null.
, Lookup , ResultFields. ResultFields.
:
- :
- TSpinEdit seBookID
- 2 TLabel - lBookName lBookAuthor .
- TButton Caption ""
- OnClick :
Var
LookupResult:variant;
Begin
LookupResult:= DataModule2.Books.Lookup("BookID",seBookID.Value, "BName;BAuthor");
if VarType(LookupResult) = varNull then
ShowMessage(" " + IntToStr(seBookID.Value))
else if VarType(LookupResult) = varEmpty then
ShowMessage(" ")
