[fpc-pascal] Patch: new XML export for FCL-DB ready for inclusion, issue 19790 - includes Delphi Clientdataset

[Ludo Brands]

> 
> Update: includes first stab at Delphi Clientdataset. Please 
> test with various datatypes as I haven't been able to map all 
> of them...
> 

Some problems with Delphi Clientdataset:

-<METADATA> comes after <ROWDATA> and Delphi 2006 complains about missing
metadata. Inverting the 2 blocks solves the problem. Moved the <METADATA>
block from 2555 to 2462 

- datetime and timestamp are missing time part as mentioned in the comments.

Formatdatetime('yyyymmdd"T"hh:nn:ss', EF.Field.AsDateTime) solves that.

- bcd: invalid field type 

- the mysql text types (tinytext,text, longtext, etc) are exported as
bin.hex with subtype binary. Perhaps a problem in the mysql code. 

- when a string field contains the > character, the row is not imported but
the previous one is duplicated. 

-Delphi has the dfXMLUTF8 and dfXML format for exporting data but no way to
specify this for reading. The difference is in the first line:
encoding="UTF-8". 

I'll investigate further and let you know by tomorrow.

Ludo

Ludo