Allow Blank Cells in Power table

Can I allow my power table to accept blank cells?

Right now, if a cell has a value, I can edit that value, but I can not delete it. The table turns the cell red and I can’t move on until entering something in the cell.

Any Ideas?
My end goal is to have NULL stored in the database, and nothing appear in the table cell.

I had the exact same issue. The only way I could get around it was to put a “Clear Cell” function in a right-click popup menu.

My code is below, in case it helps you. Note that I only wanted to fire this option on columns 3-8 inclusive. I had to define my database column names because my table headers were different. I am sure there’s a more efficient way, but it does work. All of the java stuff was to select the table cell when I right click (note that my header is two rows high so I am subtracting 32 points from the Y coordinate to account for that).

As with any popup menu, put the code in MousePressed and MouseReleased.

Any questions, let me know.

if event.button != event.BUTTON1:
	def clearCell(event):
		id =,"ID")
		colIndex = event.source.selectedColumn
		if colIndex == 3:
			dbfield = 'WTMin'
		elif colIndex == 4:
			dbfield = 'WTMax'
		elif colIndex == 5:
			dbfield = 'OOR'
		elif colIndex == 6:
			dbfield = 'OD'
		elif colIndex == 7:
			dbfield = 'SmpTime'
		elif colIndex == 8:
			dbfield = 'BoxQC'
		if system.gui.confirm("Are you sure you want to clear this cell?","Clear Cell?"):
			query = "UPDATE ShiftQC SET %s = NULL WHERE id = ?" % (dbfield)
			args = [id]
			system.db.runPrepUpdate(query, args)

if event.popupTrigger:
	#These seven lines select the correct row in the table.
	from java.awt import Point
	tbl = event.source
	jTbl = tbl.getTable()
	newY = jTbl.getVisibleRect().y
	newX = jTbl.getVisibleRect().x
	oldPoint = event.getPoint()
	newPoint = Point(oldPoint.x + newX, oldPoint.y-32)
	selCol = event.source.selectedColumn
	selRow = event.source.selectedRow

	ID =,"ID")

	if selCol in range(3,9):
		names = ["Clear this Cell"]
		functions = [clearCell]
		menu = system.gui.createPopupMenu(names, functions)