C# DataRow Empty-check

Question

I got this:

 DataTable dtEntity = CreateDataTable();
 drEntity = dtEntity.NewRow();

Then I add data to the row (or not). Lots of code, really don't know if there's anything inside the row. Depends on the input (i am importing from some files). I'd like to do something like:

 if (drEntity`s EVERY CELL IS NOT EMPTY)
 {
   dtEntity.Rows.Add(drEntity);
 }
 else
 {
   //don't add, will create a new one (drEntity = dtEntity.NewRow();)
 }

Is there some nice way to check if the DataRow's every cell is empty? Or I should foreach, and check them one by one?

Answer 1

A simple method along the lines of:

bool AreAllColumnsEmpty(DataRow dr)
{
 if (dr == null)
 {
  return true;
 }
 else
 {
  foreach(var value in dr.ItemArray)
  {
    if (value != null)
    {
      return false;
    }
  }
  return true;
 }
}

Should give you what you're after, and to make it "nice" (as there's nothing as far as I'm aware, in the Framework), you could wrap it up as an extension method, and then your resultant code would be:

if (datarow.AreAllColumnsEmpty())
{
}
else
{
}

Answer 2

You could use this:

if(drEntity.ItemArray.Where(c => IsNotEmpty(c)).ToArray().Length == 0)
{
    // Row is empty
}

IsNotEmpty(cell) would be your own implementation, checking whether the data is null or empty, based on what type of data is in the cell. If it's a simple string, it could end up looking something like this:

if(drEntity.ItemArray.Where(c => c != null && !c.Equals("")).ToArray().Length == 0)
{
    // Row is empty
}
else
{
    // Row is not empty
}

Still, it essentially checks each cell for emptiness, and lets you know whether all cells in the row are empty.

Answer 3

DataTable.NewRow will initialize each field to:

• the default value for each DataColumn (DataColumn.DefaultValue)

• except for auto-increment columns (DataColumn.AutoIncrement == true), which will be initialized to the next auto-increment value.

• and expression columns (DataColumn.Expression.Length > 0) are also a special case; the default value will depend on the default values of columns on which the expression is calculated.

So you should probably be checking something like:

bool isDirty = false;
for (int i=0; i<table.Columns.Count; i++)
{
    if (table.Columns[i].Expression.Length > 0) continue;
    if (table.Columns[i].AutoIncrement) continue;
    if (row[i] != table.Columns[i].DefaultValue) isDirty = true;
}

I'll leave the LINQ version as an exercise :)

Answer 4

Maybe a better solution would be to add an extra column that is automatically set to 1 on each row. As soon as there is an element that is not null change it to a 0.

then

If(drEntitity.rows[i].coulmn[8] = 1)
{
   dtEntity.Rows.Add(drEntity);
}
 else
 {
   //don't add, will create a new one (drEntity = dtEntity.NewRow();)
 }

Answer 5

I prefer approach of Tommy Carlier, but with a little change.

foreach (DataColumn column in row.Table.Columns)
    if (!row.IsNull(column))
      return false;

  return true;

I suppose this approach looks more simple and bright.

Answer 6

I did it like this:

var listOfRows = new List<DataRow>();
foreach (var row in resultTable.Rows.Cast<DataRow>())
{
    var isEmpty = row.ItemArray.All(x => x == null || (x!= null && string.IsNullOrWhiteSpace(x.ToString())));
    if (!isEmpty)
    {
        listOfRows.Add(row);
    }
}