Обсуждение: How to Convert VarChar to Date in PgSQL
Dear All,
I have one table which has lot of data.In the same table I have one varchar filed. I want to convert into Date data type? Is It possible to convert varchar to date datatype with out loosing data.Please guide me.I am waiting for your great response.
?Thanx & Regards
Venkat Rao Tammineni
GIS Developer
On 10/03/2009 12:07, Venkat Rao Tammineni wrote: > I have one table which has lot of data.In the same table I have one > varchar filed. I want to convert into Date data type? Is It possible to > convert varchar to date datatype with out loosing data.Please guide me.I am > waiting for your great response. If the varchar is already in the format you need (yyyy-mm-dd) then you ought to be able just to cast it: '2009-03-10'::date If not, you may need to do some clever things with regular expressions first to get it into this format, and then cast it. Ray. ------------------------------------------------------------------ Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland rod@iol.ie Galway Cathedral Recitals: http://www.galwaycathedral.org/recitals ------------------------------------------------------------------
On Tue, Mar 10, 2009 at 1:07 PM, Venkat Rao Tammineni <vtammineni@roulacglobal.com> wrote: > I have one table which has lot of data.In the same table I have one > varchar filed. I want to convert into Date data type? Is It possible to > convert varchar to date datatype with out loosing data.Please guide me.I am > waiting for your great response. An easy solution would be to add a new column to the table, of type date, and then execute an update statement that reads, for each row, the value in the varchar field and writes the converted value to the date field. -- Jaume Sabater http://linuxsilo.net/ "Ubi sapientas ibi libertas"
hello 2009/3/10 Venkat Rao Tammineni <vtammineni@roulacglobal.com>: > Dear All, > > > > > > I have one table which has lot of data.In the same table I have one > varchar filed. I want to convert into Date data type? Is It possible to > convert varchar to date datatype with out loosing data.Please guide me.I am > waiting for your great response. > > > use function to_date, please http://www.postgresql.org/docs/8.3/static/functions-formatting.html postgres=# select to_date('2009-07-17', 'YYYY-MM-DD'); to_date ---------- 2009-07-17 (1 row) regards Pavel Stehule > > > > > ?Thanx & Regards > > Venkat Rao Tammineni > > GIS Developer > >
2009/3/10 Jaume Sabater <jsabater@gmail.com>: > On Tue, Mar 10, 2009 at 1:07 PM, Venkat Rao Tammineni > <vtammineni@roulacglobal.com> wrote: > >> I have one table which has lot of data.In the same table I have one >> varchar filed. I want to convert into Date data type? Is It possible to >> convert varchar to date datatype with out loosing data.Please guide me.I am >> waiting for your great response. > > An easy solution would be to add a new column to the table, of type > date, and then execute an update statement that reads, for each row, > the value in the varchar field and writes the converted value to the > date field. > resp. alter table someatb alter column columname type date using to_data(columname, 'YYYY-MM-DD'); regards Pavel > -- > Jaume Sabater > http://linuxsilo.net/ > > "Ubi sapientas ibi libertas" > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >