I want to copy the entire content from one column to another (same datatype) and thought of a subselect to be part of the equasion.
SET column2=(SELECT column1 FROM tab01);
ERROR: more than one row returned by a subquery used as an expression
that error makes completely sense as the outpout of my subselect has many rows.
Is there a way to copy all values into the other coloumn, without creating any sort of loop around something like ...
SET column2=(SELECT column1 FROM tab01 WHERE id=1)