xml as database

[Matteo Cima]

Hi,
I googled and searched in the newsgroup, but still can't find a way to
follow, can't find any example!
I'd love to use xml as a little database for my c# app, just having 2 tables
and a few records, and I also want to do this as a "proof of concept".
What I want to do is just use select, insert into and update sql statements
on it.
I know I have to use datasets, but I can't start, because the documentation
explains the single functions but not the overview of the exact topic, so I
can't even guess how to start.
Just need a few lines of code.

Let's say i have an xml like

<person>
<name>Matteo</name>
<aka>mdm</aka>
</person>
<person>
<name>John</name>
<aka>jj</aka>
</person>


I'd love to just do a sort of "UPDATE PERSON SET AKA='JJ2' WHERE
NAME='john'"
and "INSERT INTO PERSON VALUES('Elwood', 'eb')"

Is this possible? Am I missing something, or, well, What am I missing?

Thanks for every clue.

--
Matteo Cima,
Senior Developer, Mobile Expert, Project Manager, Lead Analyst,
Dotnet, C# (Csharp) and Compact Framework Expert
Digisoft srl Italy
msn: matteodellamontagna_hotmail_com (you know what to do with those
underscores, don't you?)

 

[Nicholas Paldino [.NET/C# MVP]]

Matteo,

You aren't going to be able to do this. The reason is that manipulation
of an XML document typically requires a DOM. Also, there is no standard
mapping between SQL and XML either which will allow this kind of lnaguage
construct. Finally, there you would need a query engine which would process
this sort of thing (there is XQuery, but AFAIK, it is only for queries).

I would recommend loading the XML in a data set, and then modifying the
data set, or even modifying the XML through the DOM.

Hope this helps.

 

[Benny Mathew]

Hi,
You cannot use SQL statements directly on a dataset.
You have to use the methods provded by ADO.NET to Add/Delete/Update
records in a Dataset.

Regards
Benny

 

[Matteo Cima]

Thank you all!
Matteo

Where to start with datasets:
A dataset is basically a collection of tables, which you can access
through the Tables property, so "CREATE TABLE KUKU" is
ds.Tables.Add("Kuku"). You'll need to add columns to its Columns property.

"UPDATE PERSON SET AKA='JJ2' WHERE NAME='john'" becomes something like
foreach(DataRow dr in ds.Tables["PERSON"].Select("NAME='john'")
dr["AKA"]="JJ2";

"INSERT INTO PERSON VALUES('Elwood', 'eb')" becomes something like
DataRow dr = ds.Tables["PERSON"].NewRow();
dr["NAME"]="Elwood";
dr["AKA"]= "eb";
ds.Tables["PERSON"].Rows.Add(dr);

I hope this puts some of the pieces in place, enough to continue through
MSDN.

Uri

Hi,
I googled and searched in the newsgroup, but still can't find a way to
follow, can't find any example!
I'd love to use xml as a little database for my c# app, just having 2 tables
and a few records, and I also want to do this as a "proof of concept".
What I want to do is just use select, insert into and update sql statements
on it.
I know I have to use datasets, but I can't start, because the documentation
explains the single functions but not the overview of the exact topic, so I
can't even guess how to start.
Just need a few lines of code.

Let's say i have an xml like

<person>
<name>Matteo</name>
<aka>mdm</aka>
</person>
<person>
<name>John</name>
<aka>jj</aka>
</person>


I'd love to just do a sort of "UPDATE PERSON SET AKA='JJ2' WHERE
NAME='john'"
and "INSERT INTO PERSON VALUES('Elwood', 'eb')"

Is this possible? Am I missing something, or, well, What am I missing?

Thanks for every clue.

 

[Uri Dor]

Where to start with datasets:
A dataset is basically a collection of tables, which you can access
through the Tables property, so "CREATE TABLE KUKU" is
ds.Tables.Add("Kuku"). You'll need to add columns to its Columns property.

"UPDATE PERSON SET AKA='JJ2' WHERE NAME='john'" becomes something like
foreach(DataRow dr in ds.Tables["PERSON"].Select("NAME='john'")
dr["AKA"]="JJ2";

"INSERT INTO PERSON VALUES('Elwood', 'eb')" becomes something like
DataRow dr = ds.Tables["PERSON"].NewRow();
dr["NAME"]="Elwood";
dr["AKA"]= "eb";
ds.Tables["PERSON"].Rows.Add(dr);

I hope this puts some of the pieces in place, enough to continue through
MSDN.

Uri