This is one of three questions this week, to which, I'm afraid, the answer is no.[The others were Entity-Attribute-Value constraints and A running total]
No, you cannot do that with an SQL statement. That is, maybe you can, but there are too many potential pitfalls here, and they make me feel uncomfortably pessimistic about the likelihood that any query I come up with will actually help you.
What does "break up the number of rows and update their associated header record with a value" mean? You mentioned an approval page, and the image I have is someone sitting at a screen somewhere, looking at rows 6001 through 12000, which, if you don't mind my saying, is far too many rows to display on an approval page.
Next, you want to "update the header record, which can be multiple records with a unique value," and I am totally hamstrung. Surely a line row belongs to only one header row, so how could a count update multiple header records?
This was first published in April 2008