Under the TClientDataSet xe2 and transfers between Json? The best example is given,

CodePudding user response:

Internet has a lot of examples...

 
The unit uJSONDB; 

Interface 
USES the 
SysUtils, Classes, Variants, DB, DBClient SuperObject, Dialogs. 
Type 
TJSONDB=class 

Private 
The class function getJsonFieldNames (res: ISuperObject) : TStringList; 
The class function getJsonFieldValues (res: ISuperObject) : TStringList; 
Public 
The class procedure JsonToClientDataSet (jsonArr: TSuperArray; DstCDS: the TClientDataSet); 
The class function ClientDataSetToJSON (srcCDS: the TClientDataSet) : UTF8String; 
The end; 

Implementation 

The function GetToken (var astring: string; Const FMT: an array of char) : string; 
Var 
I, j: integer; 
Found: Boolean; 
The begin 
Found:=false; 
Result:='; 
AString:=TrimLeft (aString); 

If length (astring)=0 then the exit; 

I:=1; 
While I<=length (Astring) do 
The begin 
Found:=false; 
If aString [I] <=# 128 then 
The begin 
For j:=Low (Fmt) to High (Fmt) do 
The begin 
If (astring [I] <> Fmt [j]) then continue; 
Found:=true; 
break; 
The end; 
If Not found then I:=I + 1; 
End 
Else I:=I + 2; 

If found then break; 
The end; 

If found then 
The begin 
Result:=copy (astring, 1, I - 1); 
Delete (astring, 1, I); 
End 
The else 
The begin 
Result:=astring; 
Astring:='; 
The end; 
The end; 

The function GetFieldParams (PropName, Source: string) : string; 
Var 
S1, S2: string; 
TmpParam: string; 
AChar: string; 
AValue aPropName, aSource: string; 
The begin 
Result:='; 
If Source="' then the Exit; 
ASource:=Source; 
While aSource & lt;> ' 'do 
The begin 
AValue:=GetToken (aSource, (', ')); 
APropName:=GetToken (aValue, [' : ']); 
If CompareText (PropName, aPropName) & lt;> 0 then the continue; 
Result:=aValue; 
break; 
The end; 
The end; 
//obtained from json field name 
The class function TJSONDB. GetJsonFieldNames (res: ISuperObject) : TStringList; 
Var 
I: Integer; 
FieldList: TStringList; 
FieldNames: String; 
The begin 
Try 
FieldList:=TStringList. Create; 
FieldNames:=res AsObject. GetNames. AsString; 
FieldNames:=StringReplace (fieldNames, '[',' ', [rfReplaceAll rfIgnoreCase]); 
FieldNames:=StringReplace (fieldNames, '] ', ' ', [rfReplaceAll rfIgnoreCase]); 
FieldNames:=StringReplace (fieldNames, '"', ' ', [rfReplaceAll rfIgnoreCase]); 

FieldList. Delimiter:=', '; 
FieldList. DelimitedText:=fieldNames; 
Result:=fieldList; 
The finally 
//fieldList. Free; 
The end; 
The end; 

//field values obtained from the json 
The class function TJSONDB. GetJsonFieldValues (res: ISuperObject) : TStringList; 
Var 
I: Integer; 
FieldList: TStringList; 
FieldValues: String; 
The begin 
Try 
FieldList:=TStringList. Create; 
FieldValues:=res AsObject. GetValues. AsString; 
FieldValues:=StringReplace (fieldValues, '[',' ', [rfReplaceAll rfIgnoreCase]); 
FieldValues:=StringReplace (fieldValues, '] ', ' ', [rfReplaceAll rfIgnoreCase]); 
FieldValues:=StringReplace (fieldValues, '"', ' ', [rfReplaceAll rfIgnoreCase]); 

FieldList. Delimiter:=', '; 
FieldList. DelimitedText:=fieldValues; 
Result:=fieldList; 
The finally 
//fieldList. Free; 
The end; 
The end; 
//json CDS 
The class procedure TJSONDB. JsonToClientDataSet (jsonArr: TSuperArray; DstCDS: the TClientDataSet); 
Var 
FieldList: TStringList; 
ValuesList: TStringList; 
JsonSrc: string; 
I, j: Integer; 
The begin 

FieldList:=getJsonFieldNames (SO [jsonArr [0]. AsJson (False, False)]); 
If (dstCDS. FieldCount=0) then 
The begin 
For I:=0 to fieldList. Do the Count - 1 
The begin 
DstCDS. FieldDefs. Add (fieldList [I], ftString, 100, False); 
The end; 
DstCDS. CreateDataSet; 
DstCDS. Close; 
DstCDS. Open; 
The end; 
Try 
DstCDS. DisableControls; 
For I:=0 to jsonArr. Do Length - 1 
The begin 
JsonSrc:=SO [jsonArr [I] AsJson (False, False)]. The AsString; 
JsonSrc:=StringReplace (jsonSrc, '[',' ', [rfReplaceAll rfIgnoreCase]); 
JsonSrc:=StringReplace (jsonSrc, '] ', ' ', [rfReplaceAll rfIgnoreCase]); 
JsonSrc:=StringReplace (jsonSrc, '"', ' ', [rfReplaceAll rfIgnoreCase]); 
JsonSrc:=StringReplace (jsonSrc, '{',' ', [rfReplaceAll rfIgnoreCase]); 
JsonSrc:=StringReplace (jsonSrc, '} ', ' ', [rfReplaceAll rfIgnoreCase]); 
DstCDS. Append; 
For j:=0 to fieldList. Do the Count - 1 
The begin 
DstCDS. FieldByName (fieldList [j].) AsString:=GetFieldParams (fieldList [j], jsonSrc); 
The end; 
DstCDS. Post; 
The end; 

The finally 
DstCDS. EnableControls; 
The end; 
The end; 

The class function TJSONDB. ClientDataSetToJSON (srcCDS: the TClientDataSet) : UTF8String; 
Var 
I, j: Integer; 
KeyValue: String; 
JsonList: TStringList; 
JsonResult: String; 
The begin 
If not srcCDS. Active then srcCDS. Open; nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull