pgadmin - PostgreSQL : what are simple quotation marks for? -

pgadmin - PostgreSQL : what are simple quotation marks for? -

how remove simple quotation marks appear in empty cells? see image below

the columns can either text or character varying(), these signs still present. have other tables no quotation marks in empty cells... extract above result of importation of oracle table pgsql database. reason why.

my guess importation process introduced single quotes. if query solves it

select num_position, replace(num_position, '''', '') t;

then replace single quotes

update t set num_position = replace(num_position, '''', ''), num_plan = replace(num_plan, '''', '')

postgresql pgadmin quotation-marks