Lazarus 0.9.31+MySql server 5.5+windows 7 "Access Viola

ism · Post by **ism** » 12.04.2011, 22:07

Hello, i try to test version from svn://zeos.firmos.at/zeos/branches/testing rev 887
But the program crash when i try to write some sumbols in ztable through DBGrid
And more , the string of any length in DBGrid visible as "??" (russian chars)

this problem repeat in Windows XP and Lazarus 0.9.30 and MySql 5.1

Exception in lines ZAbstractRODataset

ftWideString:
begin
{$IFDEF BDS4_UP}
WStrCopy(Buffer, PWideChar(RowAccessor.GetUnicodeString(ColumnIndex, Result)));
{$ELSE}
line 1381 --------->PWideString(Buffer)^ := RowAccessor.GetUnicodeString(ColumnIndex, Result);
{$ENDIF}
Result := not Result;
end;

Error "Invalid Pointer operation"

test project
http://narod.ru/disk/10018079001/test_proj.7z.html

Version from http://zeosdownloads.firmos.at/downloads/snapshots/
ZEOSLIB_TRUNK_REV834.zip working good

Sorry for bad english

Dali · Post by **Dali** » 13.04.2011, 10:52

The same happened to me when testing ADO (yes, I'm aware of the lack of support of the ADO driver under Lazarus):

http://zeos.firmos.at/viewtopic.php?p=12959#12959

So, maybe it's the same problem.

Dali · Post by **Dali** » 13.04.2011, 11:24

Anyway, I tried trunk rev 834 and it crashed as well.

Dali · Post by **Dali** » 15.04.2011, 08:46

Any clues on this anyone? Please?

ism · Post by **ism** » 15.04.2011, 17:58

It happens, because not allocated memory for the pointer, when function is called

function TZAbstractRODataset.GetFieldData(Field: TField;
Buffer: Pointer): Boolean;

I'm trying to find the problematic place

ism · Post by **ism** » 15.04.2011, 18:00

Who knows where this function is called?

This only happens with DBgrid and Datasource

ism · Post by **ism** » 01.05.2011, 12:33

Details
Сreated a new project (just in case)
Any string row from the database shows as "???"

Zoran · Post by **Zoran** » 02.05.2011, 07:21

Do not forget to put the line "codepage=UTF8" in Properties property of the ZConnection.

ism · Post by **ism** » 02.05.2011, 16:35

Is not the case, I tried it.

ZConnection1.Connect;
ZSQLProcessor1.Script.Text:='SET NAMES UTF8';
ZSQLProcessor1.Execute;
ZQuery1.Open;

result - access violation

and

codepage=UTF8

result - '??.'

The strung in table is

'привет привет ... '

It must be displayed as '??????? ????????'

ism · Post by **ism** » 02.05.2011, 20:38

I found
Problem in module ZDbcMySqlUtils.pas
function ConvertMySQLTypeToSQLType(TypeName, TypeNameFull, Collation: string): TZSQLType;

Bug appeared in the revision 850, in 848 all ok.

Old procedure return STSTRING
New procedure return STUNICODESTRING

Probably a problem with the processing of type

Post by **mdaems** » 19.05.2011, 20:17

ism,

Did you check the discussion in http://zeos.firmos.at/viewtopic.php?t=2652
That's the thread that caused revision 850.
I'm not working with mysql databases using non latin1 encodings so I'm really unsure how this works/should work exactly.

Mark

Post by **mdaems** » 19.05.2011, 21:41

Found your patch and applied it in SVN rev 903

ism · Post by **ism** » 20.05.2011, 13:33

In Lazarus 0.9.30 by default all strings in UTF8

Enough

Code: Select all

ZConnection1.Connect;
ZSQLProcessor1.Script.Text:='SET NAMES utf8;';
ZSQLProcessor1.Execute;
ZQuery1.Open;

or

Code: Select all

ZConnection1.Properties='CodePage=UTF8'

ism · Post by **ism** » 20.05.2011, 13:35

If something should test, contact me

Dali · Post by **Dali** » 20.05.2011, 14:50

I think that it's the same problem in a different database protocol, so I'll say here that Zeos snv 903 is not working for me using PostgreSQL in Lazarus (from today's svn, compiled using fpc 2.4.2).

Database encoding is UTF8. I tried adding "codepage=utf8", even optionally followed by "client_encoding=utf8". In any case, it just crashes down with "invalid pointer operation".

If I do something similar to what you did, editing src/dbc/ZDbcPostgreSQLUtils.pas:

Code: Select all

  if Connection.GetCharactersetCode = csUTF8 then
    case Result of
{$IFNDEF FPC}
      stString: Result := stUnicodeString;
{$ENDIF}
      stAsciiStream: Result := stUnicodeStream;
    end;

... Then it does not crash, but all the special chars reflect as "?".