i am trying to use a parameterized query with Delphi TADOCommand:
var
s: WideString;
cmd: TADOCommand;
recordsAffected: OleVariant;
begin
cmd := TADOCommand.Create(nil);
cmd.Connection := Connection;
cmd.CommandText := 'INSERT INTO Sqm(Filename) VALUES(:filename)';
s := AFilename;
cmd.Parameters.ParamByName('filename').Value := s;
cmd.Execute();
The resulting data in the database is complete mangled:
C?:\U?s?er?s?\i??n?.A?V`A?T?O?P?I?A?\A?p?p?D??t??\L?o???l?\A?v?at??r? S?o?f?t?w?är¨? C?r??t?i??n?s?\S?o°f?t?w?r?? Q?u??li?t?y? M??t?r?i?cs?\C??S?-s?q?m?00.x?m?l
i can use a native parameterized ADO Command object. It saves the data correctly:
C̬:\Ȗŝḙr͇s̶\i̜ẵn̥.ÀV̹AͧT̶O̠P̩I̿Ȁ\A͜p̥p̔D͑ẫt̒ā\L̫o͋ɕălͭ\A̼v̼ẵt͈ấr̄ S̫o̖f͎t̻w̵ạr͂ẽ C̾r̮ḛẵt͘iͩo̳n̬s̨\S̪ōf̒t͘w̚âr̿ɇ Qͬüẳlͮi̫tͥy̽ M͘ȇt̨r̟i̻çš\C͍MͥS̚-s̞q̕m͜00.xͤm̧l̝
but it's very fragile and not suitable for production use.
How can i use unicode/WideStrings with TADOCommand in Delphi?
Bonus Chatter
In SQL Server Profiler you can see the SQL being executed:
exec sp_executesql N'INSERT INTO Sqm(Filename) VALUES(#P1)', N'#P1 char(300),#P2 text', 'C?:\Us?er?s?\i?än?.A?V?A?T?O?P?I?À\A?p?p?D?ât?a\L?o?çal¯\A?v?at??r? So?f?t?w?ar?? C?r??á?i?o?n?s?\So¸f"t?w?ar?? Q?u??l?i?ty? M??t?r?i¸?s`\C?M°S?-s?q?m?00.?m¨´l¯ '
Which points out the problem - it's building the WideString parameter as a char(300) value. Make it not broke.
The last i see of my WideString before it goes down the parameter hole is:
ParameterObject.Value := NewValue;
where
NewValue is a variant of type VT_BSTR (aka varOleStr) with the proper value
ParameterObject is a native ADO _Parameter object, with a .Type of 129 (adChar)
Even trying to force the parameter type:
cmd.Parameters.ParamByName('filename').DataType := ftWideString;
cmd.Parameters.ParamByName('filename').Value := s;
doesn't help.
Note: This question is part of a series on how to paramaterize INSERT INTO foo (value) VALUES (%s)
https://stackoverflow.com/questions/10726212/using-wrong-type-with-parameterized-query-causes-error
How big is an nvarchar(max) as far as ADO is concerned?
How to parameterize widestrings using TADOCommand parameterized query?
"Must declare the variable #myvariable" error with ADO parameterized query
How about using
cmd.Parameters.ParamByName('filename').Value := WideStringToUCS4String(s);
By the way, s is declared as widestring. is it necessary to have s as a widestring? How about just
var
s : String;
in System.pas, UCS4String (UCS-4 byte or UTF-32 bits) is declared as:
...
...
UCS4Char = type LongWord;
...
UCS4String = array of UCS4Char;
...
function WideStringToUCS4String(const S: WideString): UCS4String;
...
function UCS4StringToWidestring(const S: UCS4String): WideString;
What data type you stored the filename column as ? Can sql server 2000 handle UTF-32 string?
The answer is that it cannot be done in Delphi (5).
It might be fixed in newer versions of Delphi; but without anyone to test it we won't know.
Q.: How to parameterize widestrings using TADOCommand parameterized query?
A.: You can't. Sorry for the inconvience.
Related
Is it possible to have default values in arguments of Stored procedures of Snowflake. For the below example, I am getting error. Please help
syntax error line 1 at position 53 unexpected ''test''.
create or replace procedure test(arg1 string default 'test')
returns string not null
language sql
as
$$
begin
return arg1;
end;
$$
;
Snowflake's procedures applies polymorphism instead of using default value. This solution is when you do not want to call sp like func1(Null)
For example (sql scripting):
create or replace procedure func1(arg1 varchar, arg2 varchar)
...
create or replace procedure func1(arg1 varchar)
...
call func1(arg1 , 'some-default-value')
...
One option could be providing NULL as value and handle it at the begining of the stored procedure with COALSESCE:
create or replace procedure test(arg1 string)
returns string not null
language sql
as
$$
begin
arg1 := COALESCE(arg1, 'test');
return arg1;
end;
$$;
CALL test(NULL);
-- test
Setting a default value/values as arguments directly in Stored procedures is not available in Snowflake currently
The below link can be referred for the allowed syntax in Stored Procedures
https://docs.snowflake.com/en/sql-reference/sql/create-procedure.html#syntax
Information in form1.JvComputerInfoEx1.CPU.SSE is stored as TSSESupports.
My question is how data is actually stored in TSSESupports and how to convert to plain string?
The wiki page is not very helpful in this matter.
Look at the JCL sources.
type
TSSESupport = (sse, sse2, sse3, ssse3, sse4A, sse4B, sse5);
TSSESupports = set of TSSESupport;
So, TSSESupports is a set. Values in a set are stored bitwise.
You can test if a value is in set by "in" operator.
var
Value: TSSESupports;
begin
if sse in Value then
ShowMessage('Supports SSE');
end;
But the easiest way of converting a set into a string is using RTTI function "SetToString"
uses System.TypInfo, JclSysinfo;
var
Value: TSSESupports;
pTI: PTypeInfo;
S: string;
begin
pTI := TypeInfo(TSSESupports);
S := SetToString(pTI, Word(Value));
ShowMessage(S);
end;
I have a legacy Delphi 2 application that I need to convert from communicating with Notes via OLE Automation to communicating via COM early binding. I am using Delphi 7 since the code base is large and I want to avoid the work of dealing with the Unicode support in the more current versions of Delphi.
The basics are working: the program opens the database then the view and searches for a particular document using the NotesView.GetDocumentByKey method. The GetDocumentByKey call works when the first parameter is a single string cast to an OleVariant as shown below (opening of DB and view not shown).
var
Key: OleVariant;
const ExactMatch: WordBool = True;
begin
Key := 'AKeyValue';
Doc := View.GetDocumentByKey(Key, ExactMatch);
The bad variable type error occurs when the first parameter is a variant array as required when it is desired to search the view based on multiple columns as shown below.
var
TwoKeysV: OleVariant;
const ExactMatch: WordBool = True;
begin
TwoKeysV := VarArrayCreate([0, 1], varOleStr);
TwoKeysV[0]:= WideString('Key1');
TwoKeysV[1]:= WideString('Key2');
Doc := View.GetDocumentByKey(TwoKeysV, ExactMatch);
I have tried several variations on the two key assignment statements with no success. For example, just assigning the key string without a cast still produces the bad variable type, and using the StringToOleString function is rejected by the compiler as an invalid assignment (PWideChar to Variant).
I can't test this, so I'm not sure this works.
HELP: If this method is used under COM, with a keyArray parameter of an array, it must be defined as an array of type Variant
So you need to pass: an array of type Variant
Based on How to use variant arrays in Delphi.
Note: Code edited by Keeloid to match code that worked by casting key string to WideString.
var
TwoKeysV: OleVariant;
const ExactMatch: WordBool = True;
begin
TwoKeysV := VarArrayCreate([0, 1], varVariant);
TwoKeysV[0]:= WideString('Key1'); {WideString = varOleStr}
TwoKeysV[1]:= WideString('Key2');
Doc := View.GetDocumentByKey(TwoKeysV, ExactMatch);
I tried to pass a database record from my server-side application to my client-side application. On the client-side I need to store my data into a TStrings collection.
When I pass a multiline field, I receive two separate data items at the client-side, instead of one multiline data item! I've also tried to do that with Unicode UTF8 based commands, but unfortunately the result is same.
Server-side code:
procedure TForm1.IdCmdTCPServer1CommandHandlers0Command(ASender: TIdCommand);
var
myData: TStrings;
begin
myData := TStringList.Create;
myData.Add('12'); // ID
myData.Add('This is a multi line' + #13#10 + 'description.'); // Descriptions
myData.Add('Thom Smith'); // Name
try
ASender.Context.Connection.Socket.Write(myData, True{, TIdTextEncoding.UTF8});
finally
myData.Free;
end;
end;
myData debug-time values on server-side are:
myData[0] = '12'
myData[1] = 'This is a multi line'#$D#$A'description.'
myData[2] = 'Thom Smith'
Client-side code:
procedure TForm1.Button1Click(Sender: TObject);
var
myData: TStrings;
begin
with TIdTCPClient.Create(nil) do
begin
Port := 1717;
Host := 'localhost';
try
Connect;
//IOHandler.DefStringEncoding := TIdTextEncoding.UTF8;
myData := TStringList.Create;
try
SendCmd('greating');
Socket.ReadStrings(myData, -1{, TIdTextEncoding.UTF8});
eID.Text := myData[0]; // ID TEdit
mDes.Text := myData[1]; // Descriptions TMemo
eTelNo.Text := myData[2]; // Name TEdit
finally
myData.Free;
end;
finally
Disconnect;
Free;
end;
end;
end;
myData debug-time valuese on client-side:
myData[0] = '12'
myData1 = 'This is a multi line'
myData[2] = 'description.'
Telnet result:
Actually, myData[2] that should keep 'Thom Smith' was replaced with the second line of the Description field! and there are no items after myData[2]. myData[3] is not accessible any more.
I think this issue is related to Indy's Write or ReadStrings procedures, because it sends ItemCount as 3, but it sends two items (one correct, and next beaked to two items!).
How can I pass a Carriage Return character to the other side without having the Write procedure break myData[1] into two separate lines?
Thanks a lot.
If you want TStrings.Text be oblivious to special characters - you should escape them before sending by net, and un-escape after that. There are a lot of ways of escaping, so choose one that suits you.
function EscapeString:(String): String --- your choice
function DeEscapeString:(String): String --- your choice
procedure SendEscapedStrings(const socket: TIdSocket; const data: TStrings);
var s: string; temp: TStringList;
begin
temp := TStringList.Create;
try
temp.Capacity := data.Count;
for s in data do
temp.Add( EscapeString( s ) );
socket.Write(temp);
finally
temp.Destroy;
end;
end;
procedure ReadDeescapedStrings(const socket: TIdSocket; const data: TStrings);
var s: string; temp: TStringList;
begin
temp := TStringList.Create;
try
Socket.ReadStrings(temp, -1);
data.Clear;
data.Capacity := temp.Count;
for s in temp do
temp.Add( DeEscapeString( s ) );
finally
temp.Destroy;
end;
end;
Now the question is what would you choose for DeEscapeString and EscapeString ? The options are many.
You can choose convert string to base64 before sending and from base64 after reading
You can choose UUEEncode for escapgin and UUEDecode for de-escaping
You can choose yEnc: http://en.wikipedia.org/wiki/YEnc
Or you can choose very simplistic functions StrStringToEscaped and StrEscapedToString from JclString unit of from Jedi CodeLib ( http://jcl.sf.net ):
what kind of escaping
If you ask for suggestion i would suggest not using raw TCP Server. There is well-known and standard HTTP protocol, there are many libraries for Delphi implementing both HTTP server and HTTP client. And in the protocol (and libraries) there are already decided things like ciphering, compressing, languages support, etc. And if somethign goes wrong - you can take any HTTP sniffer and see who is in the wrong- clent or server - with your own eyes. Debugging is much simpler.
If you are just starting, i suggest you looking into HTTP+JSON Synopse mORMot library, maybe it would cover your needs. You can take sample server code from http://robertocschneiders.wordpress.com/2012/11/22/datasnap-analysis-based-on-speed-stability-tests/ for example, or from demos in the lib.
Then, if to arrange around raw TCP server, i'd send compressed data, so it would work better (networks are slower than CPU usually). See http://docwiki.embarcadero.com/CodeExamples/XE5/en/ZLibCompressDecompress_(Delphi).
Sending:
1: Send into network (int32) - TStringList.Count
2: for every string doing
2.1 creating TStringStream from the string[i]
2.2 passing it via TZCompressionStream
2.3 sending (int32) size of compressed data
2.4 sending the data itself
2.5 freeing the temporary streams
Receiving
1: Receive from net (int32) - count of packets
1.1 ResultStringList.Clear; ResultStringList.Capacity := read_count.
2: for every string doing
2.1 creating TBytesStream
2.2 read from net (int32) size of compressed data
2.3 read N bytes from the network into BytesStream
2.4 unpack it via TZDecompressionStream into TStringStream
2.5 ResultStringList.Add( StringStream -> string );
2.6 freeing the temporary streams
Now, if you really don't want ot change almost anything, then JCL escaping would hopefully be enough for you. At least it worked for me, but my task was very different and was not about networks at all. But you can just test them all and see how it works for you.
Don't use the TStrings overload as it seems to use line breaks as separator between strings which does not work if your strings contain line breaks themselves.
You can easily write your own wrapper method to send a list of strings over the wire (take that as pseudocode):
procedure WriteStrings(IOHandler : TIdIOHandler; Strings : TStrings);
var
Str : String;
begin
IOHandler.WriteBufferOpen;
try
IOHandler.Write(Strings.Count);
for Str in Strings do
IOHandler.Write(Str);
finally
IOHandler.WriteBufferClose;
end;
end;
procedure ReadStrings(IOHandler : TIdIOHandler; Strings : TStrings);
var
Count, I : Integer;
begin
Count := IOHandler.ReadInteger;
for I := 1 to Count do
Strings.Add(IOHandler.ReadString);
end;
I have a firebird 2.x database with Generator and a trigger to generate the key field.
I need to get the returned value from below query.
INSERT INTO XXXX (vdate,description) values ('"+ VDate +"','"+ Description +"') returning vno INTO :ParamVoucherNo
I tried several versions of below code but it dont wrok and I get
Dynamic sql error sql error code = -104
Is it really possible to get the return value in delphi using TIBQuery ?
Query1->SQL->Clear();
Query1->SQL->Add("INSERT INTO XXXX (vodate,description) values ('"+ VDate +"','"+ Description +"') returning vno INTO :ParamVoucherNo");
Query1->Params->ParamByName("ParamVoucherno")->ParamType = ptResult;
Query1->Params->ParamByName("ParamVoucherno")->DataType = ftInteger;
Query1->Params->ParamByName("ParamVoucherno")->Value = "";
Query1->Prepare();
Query1->ExecSQL();
Any suggestions?
From Firebird README.returning:
The INTO part (i.e. the variable list) is allowed in PSQL only (to
assign local variables) and rejected in DSQL.
As IBX uses DSQL, you should exclude INTO part from your query.
INSERT ... RETURNING for DSQL looks the same as a call of a stored procedure, which returns result set. So, you have to use Open instead of ExecSQL.
Your mixing of dynamic SQL with parameters is just confusing.
Do this instead:
Query1->SQL->Clear();
Query1->SQL->Add("INSERT INTO table1 (vodate,description) VALUES"+
"(:VoDate,:Description) RETURNING vno INTO :VoucherNo ");
Query1->Params->ParamByName("VoDate")->Value = VDate;
Query1->Params->ParamByName("description")->Value = Description;
Query1->Prepare();
Query1->ExecSQL();
VoucherNo = Query1->Params->ParamByName("VoucherNo")->AsInteger;
Using Delphi 6 I have the ID returning successfully using an EXECUTE BLOCK statement:
EXECUTE BLOCK
RETURNS ( DeptKey INT )
AS
BEGIN
INSERT INTO DEPARTMENT
( COMPANY_KEY, DEPARTMENT_NAME )
VALUES ( 1, 'TEST1' ) RETURNING DEPARTMENT_KEY INTO :DeptKey;
SUSPEND;
END;
From Delphi you can do the folliowing:
FQuery.SQL.Text := '<Execute Block Statement>';
FQuery.Open();
ANewKey := FQuery.Fields[0].AsInteger;
IBX is not Firebird ready
you can take a look at FIBPLUS who support Firebird features
FIBPlus also supports FB2.0 insert ... into ... returning. Now you
should not bother about getting generator values from the client but
leave them in the trigger. You can also use RDB$DB_KEY. New possible
variants of work with insert returning and RDB$DB_KEY are shown in the
example “FB2InsertReturning”.
Why not get the next value for VoucherNo first, followed by
"INSERT INTO table1 (vno, vodate,description) VALUES (:VoucherNo,:VoDate,:Description)");
?
Your trigger can then either be dispensed with (which is nice), or modified to detect null (or <= zero can be useful too) and only then populate the vno field.
create trigger bi_mytable
active before insert position 1
on mytable
as
begin
if (new.vno is null)
then new.vno = next value for gen_VoucherNos;
end
Client-side you can :
select gen_id(gen_VoucherNos, 1) from rdb$database;
By modifying the trigger in this manner you save yourself a headache later on if/when you want to insert blocks of records
I wonder if that INSERT can be wrapped into EXECUTE BLOCK command.
Would IBX manage EXECUTE BLOCK then?
http://www.firebirdsql.org/refdocs/langrefupd20-execblock.html
http://firebirdsql.su/doku.php?id=execute_block
Hope to try it in both IBX and Unified Interbase in XE2
PS: Even if it does not, I found the library, that tells to work on top of IBX of Delphi XE2 (both x86 and x64) and to add EXECUTE BLOCK support: http://www.loginovprojects.ru/index.php?page=ibxfbutils#eb.
As I know there should be some changes to IBX made. Internally INSERT ... RETURNING should be treated the same way as a selectable procedure with returning parameters.
i know this question was answered a long time ago, but i must write this as clear as possible, for those who need this as i was.
i too, needed the "INSERT..RETURNING" thing.
the Delphi drove me crazy for a long time, until i changed my Data access components.
i even moved from Delphi XE2, to XE5 only because of that...
conclusion : IBX does NOT support RETURNING!
FireDAC is PERFECT for what i need with Firebird.
just move to FireDAC and you'll be able to do everything you need, and with high performance.
If you have a table with this 2 Fields: GRP_NO and GROUPNAME and you want to get the new GRP_NO you have to use RET_ as prefix, see example:
procedure TFormDatenbank.Button1Click(Sender: TObject);
var
q: Uni.TUniQuery;
ID: Integer;
GroupName: String;
begin
GroupName := 'MyGroupName';
q := TUniQuery.Create(nil);
try
q.Connection := Datenmodul.UniConnection;
q.ParamCheck := true; // the default value of ParamCheck is true.
q.SQL.Clear;
q.SQL.Add('SELECT GRP_NO, GROUPNAME FROM GROUPDATA WHERE GROUPNAME = :GROUPNAME');
q.ParamByName('GROUPNAME').AsString := GroupName;
q.Open;
if q.RecordCount > 0 then
ID := q.FieldByName('GRP_NO').AsInteger
else
begin
// there exist no group with this name, so insert this new name
q.SQL.Clear;
q.SQL.Add('INSERT INTO GROUPDATA');
q.SQL.Add('(GROUPNAME)');
q.SQL.Add('VALUES');
q.SQL.Add('(:GROUPNAME)');
q.SQL.Add('RETURNING GRP_NO;');
q.ParamByName('GROUPNAME').AsString := GroupName;
q.Execute;
ID := q.ParamByName('RET_GRP_NO').AsInteger;
end;
finally
q.Free;
end;
end;
From the IBx2 sources, you can do it like this:
//Uses IBSql;
//var Cur: IResults;
IBSQL1.SQL.Text := 'delete from tbl_document where id = 120 returning id;';
IBSQL1.Prepare;
if IBSQL1.Prepared then
begin
Cur := IBSQL1.Statement.Execute(IBTransaction1.TransactionIntf);
WriteLn(Cur.Data[cou].AsString);
Cur.GetTransaction.Commit(True);
end;
IResults interface Code:
IResults = interface
function getCount: integer;
function GetTransaction: ITransaction;
function ByName(Idx: String): ISQLData;
function getSQLData(index: integer): ISQLData;
procedure GetData(index: integer; var IsNull:boolean; var len: short; var data: PChar);
procedure SetRetainInterfaces(aValue: boolean);
property Data[index: integer]: ISQLData read getSQLData; default;
property Count: integer read getCount;
end;
Test enviroment:
Arch Linux X86
Firebird 3
Lazarus 1.9
FPC 3.0.4
Quick note: This works on new Firebird API in the IBX, But I didn't test it in Legacy Firebird API with the IBX.