C# – How to check if a column exists in a datatable

argumentexceptioncdatatable

I have a datable generated with the content of a csv file. I use other information to map some column of the csv (now in the datatable) to information the user is required to fill.

In the best world the mapping would be alway possible. But this is not reality… So before I try to map the datatable column value I would need to check if that column even exist. If I don't do this check I have an ArgumentException.

Of course I can check this with some code like this :

try
{
    //try to map here.
}
catch (ArgumentException)
{ }

but I have for now 3 columns to map and some or all might be existing/missing

Is there a good way to check if a column exist in a datatable?

Best Answer

You can use operator Contains,

private void ContainColumn(string columnName, DataTable table)
{
    DataColumnCollection columns = table.Columns;        
    if (columns.Contains(columnName))
    {
       ....
    }
}

MSDN - DataColumnCollection.Contains()

Related Solutions

C# – LINQ query on a DataTable

You can't query against the DataTable's Rows collection, since DataRowCollection doesn't implement IEnumerable<T>. You need to use the AsEnumerable() extension for DataTable. Like so:

var results = from myRow in myDataTable.AsEnumerable()
where myRow.Field<int>("RowNo") == 1
select myRow;

And as @Keith says, you'll need to add a reference to System.Data.DataSetExtensions

AsEnumerable() returns IEnumerable<DataRow>. If you need to convert IEnumerable<DataRow> to a DataTable, use the CopyToDataTable() extension.

Below is query with Lambda Expression,

var result = myDataTable
    .AsEnumerable()
    .Where(myRow => myRow.Field<int>("RowNo") == 1);

C# – How to cast int to enum

From an int:

YourEnum foo = (YourEnum)yourInt;

From a string:

YourEnum foo = (YourEnum) Enum.Parse(typeof(YourEnum), yourString);

// The foo.ToString().Contains(",") check is necessary for enumerations marked with an [Flags] attribute
if (!Enum.IsDefined(typeof(YourEnum), foo) && !foo.ToString().Contains(","))
{
    throw new InvalidOperationException($"{yourString} is not an underlying value of the YourEnum enumeration.")
}

Update:

From number you can also

YourEnum foo = (YourEnum)Enum.ToObject(typeof(YourEnum) , yourInt);

Best Answer

Related Solutions

C# – LINQ query on a DataTable

C# – How to cast int to enum

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