text to timestamp in postgresql - postgresql

Question

In the view I have a text column which contains a timestamp in this format '20/03/2018 00:00' and I'm trying to make a selection with a between clause but it's not working
SELECT id,entry_date
FROM v_view
WHERE entrada BETWEEN to_timestamp('20/03/2018 00:00','DD/MM/YYYY')::timestamp and to_timestamp('22/03/2018 00:00')::timestamp
order entry_date
with this error message
ERROR: el operador no existe: text >= timestamp without time zone
LINE 3: WHERE entry_date BETWEEN to_timestamp('20/03/2018 00:00','DD/MM.

Answer 1

you need to convert the entrada column value to a timestamp.
Also: casting the result of to_timestamp() to a timestamp is useless because to_timestamp() already returns a timestamp
SELECT id,entry_date
FROM v_view
WHERE to_timestamp(entrada, 'dd/mm/yyyy hh24:mi')
BETWEEN to_timestamp('20/03/2018', 'DD/MM/YYYY')
and to_timestamp('22/03/2018', 'dd/mm/yyyy')
order entry_date;
I prefer to use ANSI SQL timestamp literals over the to_timestamp function:
SELECT id,entry_date
FROM v_view
WHERE to_timestamp(entrada, 'dd/mm/yyyy hh24:mi')
BETWEEN timestamp '2018-03-20 00:00:00'
and timestamp '2018-03-22 00:00:00'
order entry_date
Do not store date, time or timestamp values in a text or varchar column. You should define that column as timestamp then you don't need to convert anything and you don't need to deal with invalid timestamp values in that column.