interface
 
uses
System.SysUtils,
System.StrUtils,
System.Variants;
 
function VarToSql(const pValue: Variant; pTrimToNull: Boolean = True; 
pDateTimeFormat: string = 'dd.mm.yyyy hh:nn:ss:zzz'; 
pQuoteDate: Boolean = True; pQuoteDateChar: Char = ''''; 
pNullString: string = 'NULL'): string;
 
 
implementation
 
function VarToSql(const pValue: Variant; pTrimToNull: Boolean; 
pDateTimeFormat: string; pQuoteDate: Boolean; pQuoteDateChar: Char; 
pNullString: string): string;
var
FDecimalSeparatorOld: Char;
FValue              : Variant;
begin
FValue := pValue;
if pNullString.Trim.IsEmpty then
pNullString := 'NULL';
case AnsiIndexText(VarTypeAsText(VarType(FValue)), ['FMTBcdVariantType']) of
0:
FValue := VarAsType(FValue, varDouble);
// poderão ser adicionados mais tipos específicos
end;
 
// varSingle, varDouble, varCurrency
if VarIsFloat(FValue) then
with FormatSettings do
begin
FDecimalSeparatorOld := DecimalSeparator;
DecimalSeparator := '.';
Result := FloatToStr(FValue, FormatSettings);
DecimalSeparator := FDecimalSeparatorOld;
end;
 
{varSmallInt, varInteger, varBoolean, varShortInt, varByte, varWord, 
varLongWord, varInt64, varUInt64}
if VarIsOrdinal(FValue) then
Result := VarToStr(FValue);
 
// varOleStr, varString, varUString
if VarIsStr(FValue) then
Result := QuotedStr(FValue);
 
// varDate
if VarIsType(FValue, varDate) then
Result := IfThen(pQuoteDate, AnsiQuotedStr(FormatDateTime(pDateTimeFormat, 
VarToDateTime(FValue)), pQuoteDateChar),
FormatDateTime(pDateTimeFormat, VarToDateTime(FValue)));
 
if ((VarIsClear(FValue)) or (VarIsNull(FValue)) or 
(VarIsEmpty(FValue)) or (VarIsError(FValue))) then
Result := pNullString;
 
if pTrimToNull then
if (Result.Trim.IsEmpty) or (Result.DeQuotedString.Trim.IsEmpty) then
Result := pNullString;
end;

Sql := VarToSql(DateEdit.Date);
Sql := VarToSql(DataSet.FieldByName('valor').AsCurrency);
Sql := VarToSql(FNome);