Bug in dataset filter when filtering fixed character fields

[a-s-z]

Hi,

I have a problem when activating a filter in a dataset and the filtered field ist a fixed character field.

The field description yields Length = 1 and Size = 4, the Filter expression is NODETYPE = 'P'.
When activating the filter, not all records are found.
I have searched the sources and finally looked into TData.GetField and TData.GetFieldDataAsVariant which seem to work differently, when FieldDesc.Fixed is true.

Debugging into the function TData.Eval revealed, that the field data is not converted correctly in GetFieldDataAsVariant (MemData.pas ~l.3138) compared to GetField (~l.2831)?

Can you please send me a hotfix for this issue if it is a bug?

Regards

[AlexP]

Hello,

Thank you for the information.
We have reproduced the problem.
We will try to fix it in the nearest product version.

[a-s-z]

Hi,

this bug is critical for me. When will you release next version?

In the meantime I have patched GetFieldDataAsVariant by replacing the code for widestring (ansi uses PtrToStringAnsi):

Code: Select all

      if Field.Fixed then
      begin
        t := TrimFixedChar;
        l := Field.Length;
      end
      else
      begin
        t := TrimVarChar;
        l := -1;
      end;
      if t then
      // trim fixed char values
        Value := TrimRight(Marshal.PtrToStringUni(FieldData, l))
      else
        Value := Marshal.PtrToStringUni(FieldData, l);

Please provide code patch, if there is more to do and next release takes a while. Thanks.

Regards

[AlexP]

hello,

We have already fixed this problem, this fix will be included to the next build, which will be released in the beginning of the next month.
For the time being, you should correct the PrepareBlock method in the OraClasses module as follows.

The following code

Code: Select all

else begin
            if (FieldDesc.DataType = dtString) and
               (FieldDesc.SubDataType in [dtFixedChar, dtFixedNChar])
            then
              if FieldDesc.SubDataType in [dtFixedChar, dtFixedNChar] then
                Marshal.WriteByte(Ptr, FieldDesc.Offset + FieldDesc.Length, 0)
            else if (FieldDesc.DataType = dtWideString) and
                    (FieldDesc.SubDataType in [dtFixedWideChar, dtFixedNWideChar])
            then
              if FieldDesc.SubDataType in [dtFixedWideChar, dtFixedNWideChar] then
                Marshal.WriteInt16(Ptr, FieldDesc.Offset + FieldDesc.Length * 2, 0);
          end;

should be replaced with (2 if operators should be removed):

Code: Select all

         else begin
            if (FieldDesc.DataType = dtString) and
               (FieldDesc.SubDataType in [dtFixedChar, dtFixedNChar])
            then
              Marshal.WriteByte(Ptr, FieldDesc.Offset + FieldDesc.Length, 0)
            else if (FieldDesc.DataType = dtWideString) and
                    (FieldDesc.SubDataType in [dtFixedWideChar, dtFixedNWideChar])
            then
              Marshal.WriteInt16(Ptr, FieldDesc.Offset + FieldDesc.Length * 2, 0);
          end;