Question

I searched around quite a bit, it would be great if someone could link me to a solution or answer my query.
The thing is I have a postgresql table that contains a lot of single quotes and I cant figure out how to get rid of them, because obviously this

  update tablename set fieldname= NULL where fieldname=' ; 

wont work.

Answer 1

Better use replace() for this:

UPDATE tbl SET col = replace(col, '''', '');

Much faster than regexp_replace(), and it replaces "globally": all occurrences of the search string. To achieve the same with regexp_replace(), add an optional 4th parameter:

UPDATE tbl SET col = regexp_replace(col, '''', '', 'g');

'g' for "globally".

Aside: the canonical (and SQL standard) way to escape single quotes (') in string literals is to double them (''). Using Posix style escape sequences works, too, of course. See:

• Insert text with single quotes in PostgreSQL