Transposing rows to columns

Today, I saw a question in an orkut SQL forum where the guy wanted to transpose rows to columns.

I replied to it.

Let me explain about it.

See this snapshot. I do a query of my test2 table. There are 2 rows. And the 4 weekly data has to be extracted into single column.

See, there are 4 columns that need to be turned into 1 column in 4 rows. So we need to do a cartesian join 4 times. So I use this table below.

See the cartesian join done and the results. See that each ord_no appears 4 times.

Now, using decode, I am getting only what I need.