How to clone DataTable structure excluding all data, schemas and data table constraints?

Help Activities
1

Hi,
After calling the SQL query by Execute Query Activity
image

the result is stored in System.Data.DataTable, which inherits the column schema from core SQL Data Base, eg. DateTime, Double.

I want to clone this table to a new one:
The new table is to contain the general layout of the old table, that is: all columns and their names.

The new table must not contain restrictions on the data type it stores and values.

Visualization:
From this:
image

To this:
image

How can this be achieved?

I need to make changes to the data in the table. For example, convert Double (0,155) to a value expressed in % (15,5%), change the date format, etc.

After changes: new table will looks like:
image

2

@Adrian_Star
newDT = OldDT.Clone
afterwards you can finetune / adopt the cloned Datatable

as it looks that you are only interested on the columnnames as alternate do following:

For each activity - TypeArgument: String - Values: oldDT.Columns.Cast(of DataColumn).Select(Function (x) x.ColumnName).toArray

so you will iterate over the names and can used within an add DataColumn on a new DataTable

1 Like
3

I’ve tried, but Clone clones the structure of the DataTable, including all DataTable schemas and constraints.

After Clone old data table to new one I have error:

RemoteException wrapping System.ArgumentException: Input string was not in a correct format.Couldn't store <15%> in Dbl Column.  Expected type is Double.  ---> RemoteException wrapping System.FormatException: Input string was not in a correct format.

I also tried:

.DefaultView().ToTable()

and it doesn’t work either.

4

please read again the post and give a try on second option.
DataTableVar.Clone will keep the datatype

5

Works!
Is there any function / method or LINQ available to not do it in a for each loop?

DT_Old.Columns.Cast(of DataColumn).Select(Function (x) x.ColumnName).toArray

image
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6

it could look like this:

Variables:
grafik

flow:
grafik

Result:
grafik

Kindly note: this approach risks to fall into a blackbox case and it is up to your code guideline / development rules to use it or not.

1 Like
7

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