Can't get Dapper to handle SQL RowVersion properly




I've got a rowversion column added to my database and I'm trying to get Dapper mapping to populate it properly on my object.


My object has...



```
public byte[] RowVersion { get; set; }

```

And I have included the RowVersion column in my query but when I do a Query..



```
conn.Query<MyObject, AnotherObject, AnAdditionalObject>(...

```

The MyObject that I get passed to me has a null for the RowVersion property.


If I do a Dapper Query() without any type then the dynamic I get back has the expected RowVersion on it with the correct value.


Has anyone had this working and if so what am I doing wrong?
I was able to resolve this thanks to the mental knock from Panagiotis Kanavos. I started simplifying my query to be able to post it and realized that I had placed the RowVersion column in the incorrect place of my select statement so it was being sent to `AnotherObject` instead of MyObject


Thanks for that.
I have figured out this issue and so for anyone else with the same issue.

In Designer for your XDP make sure you have a subform as the entry for the table row, and make this subform "Repeat Subform for Each Data Item" I found the subform could not be within another subform for this option to be visible.

So after this you can assign the row to the subform and the elements to the elements within the subform and hopefully it'll work.




[View solution in original post](/t5/adobe-experience-manager-forms/dynamic-rows-in-a-table-issue-also-relates-to-having-elements/m-p/204725#M6246) Turns out If I tweked each method 



```
foreach (var dataColumn in readFields.Select(column => new DataColumn(columntypeof(string)) { AllowDBNull = true, DefaultValue = string.Empty }))
{
    csvData.Columns.Add(dataColumn);
}

```

and in the second Method I changed it to use an index rather than column name



```
for (var count = 0; count < table.Columns.Count; count++)
{
    sqlBulkCopy.ColumnMappings.Add(count, count);
}

``` hello [@saurabhgupta](/u/saurabhgupta) :wave:

i’m afraid that the last updated column isn’t supported by our api at this time. this is because it’s calculated client side. you can see a list of these column types here - <https://monday.com/developers/v2#column-values-section-auto-calculated-column>

although the api do… Did you bind the listBox1, using DataSource property from DataTable?  

If so, you have to 1st get the item and value from listBox item and add it some other place (in your case to listBox2):



```
for(int i = 0; i < listBox1.SelectedItems.Count; i++)
{
     DataRowView view = listBox1.SelectedItem as DataRowView;
     string item = view["ColumnNameOfItem"].ToString(); //can be some name
     int value = Convert.ToInt32(view["ColumnNameOfValue"]);  //can be some id (number)
     listBox2.Items.Add(item); // it you want to add item (you can add value as well);
}
```

ColumnNameOfItem (or OfValue) are the names of fields in your dataTable (and same are in dataBase as well). Insteads of names you can use indexes (0 and 1, but without quotation marks).



Hope it helps.  

bye [@whyyouandi](/u/whyyouandi)

[image] whyyouandi:

i want to append another column of data.

you can add a column with [add data column] activity.

<https://www.uipath.com/activities-guide/add-data-column>

[image] whyyouandi:

and then edit the scrap date per row.

and to add a value to a target column, ch… If I am not wrong, you are trying to read or loop through the rows from datatable. This error states that the datasource(DataTable) is not having any rows. To avoid this exception use this before you read or loop through datatable:  


```
if(dt.Rows.Count  > 0 ){
     //Do your stuff here.
}
```
  

  

  

--Amit A couple of notes to get started:



> 
> .apply(literal\_eval)
> 
> 
> 


Wouldn't this be better as `map`?



> 
> I then re-create the Dask DF:
> 
> 
> ddf = dd.from\_pandas(ddf\_out, npartitions=nCores)
> 
> 
> 


`ddf_out` was already a dask dataframe, I don't know why you had to do this.



> 
> The columns in result seem to match those in metadir.
> 
> 
> 


The value of `result.columns` is taken from the meta you provided, no computing happens until you ask for it (dask is lazy in most operations). Does the ValueError exception not provide further information?


Here is a full example



```
x = ({'F9_07_PZ_COMP_DIRECT': '0',
  'F9_07_PZ_DIRTRSTKEY_NAME': 'DEBRA MEALY',
  'F9_07_PZ_COMP_OTHER': '0',
  'F9_07_PZ_COMP_RELATED': '0',
  'F9_07_PZ_TITLE': 'CHAIR PERSON',
  'F9_07_PZ_AVE_HOURS_WEEK': '1.00',
  'F9_07_PC_TRUSTEE_INDIVIDUAL': 'X'},
 {'F9_07_PZ_COMP_DIRECT': '0',
  'F9_07_PZ_DIRTRSTKEY_NAME': 'HELEN GORDON',
  'F9_07_PZ_COMP_OTHER': '0',
  'F9_07_PZ_COMP_RELATED': '0',
  'F9_07_PZ_TITLE': 'VICE CHAIR',
  'F9_07_PZ_AVE_HOURS_WEEK': '1.00',
  'F9_07_PC_TRUSTEE_INDIVIDUAL': 'X'})
df = pd.DataFrame({'a': x})
d = dd.from_pandas(df, 1)
meta = pd.DataFrame(columns=['F9_07_PZ_COMP_DIRECT', 
       'F9_07_PZ_DIRTRSTKEY_NAME',
       'F9_07_PZ_COMP_OTHER', 'F9_07_PZ_COMP_RELATED', 'F9_07_PZ_TITLE',
       'F9_07_PZ_AVE_HOURS_WEEK', 'F9_07_PC_TRUSTEE_INDIVIDUAL'], dtype="O")
d.map_partitions(lambda df: df.a.apply(pd.Series), meta=meta).compute()

```

How did I know what `meta` to use? I applied the function to the pandas dataframe - you might use a small piece of the dataframe to do this.


Some additional notes:


* it is an anti-pattern to load the data with pandas, pass to dask workers and then gather the whole result back to a pandas (in memory) dataframe, you are very unlikely to see a speedup this way and may incur a lot of overhead. You are better off loading with something like `dd.read_csv`, and aggregating or writing with dask functions too. Only `compute()` on something that will be small or not return anything (because it involves writing the output). The official examples do not use from\_pandas.
* string and dict processing are python methods, and so hold the interpreter lock (GIL) of any python function: threads will not actually run in parallel. To get parallelism, you need to run in processes, which is most easily achieved using <https://docs.dask.org/en/latest/setup/single-distributed.html>
* the distributed scheduler also gives you access to the dashboard, which has a lot of useful information to diagnose how your system is running. You can also configure a lot about its behaviour, in case you have firewall rules you need to obey. You can provide an optional parameter to the scaffolding command to update only the table you target.



```
Scaffold-DbContext "Server=(localdb)\mssqllocaldb;Database=DatabaseName;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir DirectoryNameOfYourModels -Tables employee -f

```

If you are using .net core cli then use.



```
dotnet ef dbcontext scaffold "Server=(localdb)\mssqllocaldb;Database=DatabaseName;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -o DirectoryNameOfYourModels -t employee -f

``` unfortunately that's not how it works. it's db mapping, and we're talking about joined-tables hierarchy. so the "other side" of the association must be in the referenced table (the detail one, not custom detail). use the query string to pass the venue id to the generic venue display page, make your <a> tags ref that page with "?id=xxx" at the end, from the venue page fetch that xxx value and query your db for that specific venue, and display that venue's fields as you like.


$myvar = $\_GET['id']; and thus  

Select * FROM table WHERE field='$myvar'