The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/9.5/static/sql-update.html
Description:
Does the Update command update the columns in the order they are listed? Can
an updated column's new value be used in the value calculation for a
subsequent column?
i.e. update mytable set qty=qty+5,price=price*1.1,subtotal=qty*price
Will the subtotal be calculated based on the old column values or the new
column values?
