I do not really know how to explain this in a clear manner. Please see attached image

I have a table with 4 different columns, 2 are identical to each other (NAME and QTY). The goal is to compare the differences between the QTY, however, in order to do it. I must: 1. sort the data 2. match the data item by item This is not a big deal with small table but with 10 thousand rows, it takes me a few days to do it.

Pleas help me, I appreciate.

My logic is: 1. Sorted the first two columns (NAME and QTY) 2. For each value of second two columns (NAME and QTY), check if it match with first two column. If true, the insert the value. 3. For values are not matched, insert to new rows with offset from the rows that are in first two columns but not in second two columns