Making "invisible" characters visible ? (psql)

Started by stanover 6 years ago4 messagesgeneral
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#1stan
stanb@panix.com

I added a column to an existing table, so there should be nothing (actually
the default, I suppose) in this column for all existing rows.

However if I do:

select new_column from modified_table ;

I get the total number of rows in the table, but the lines on the screen
have no visible characters. I was expecting these to be nulls, and this
select to return nothing.

How can i make these "invisible" characters visible?

--
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
-- Benjamin Franklin

#2Brian Dunavant
dunavant@gmail.com
In reply to: stan (#1)
Re: Making "invisible" characters visible ? (psql)

On Wed, Nov 20, 2019 at 9:16 AM stan <stanb@panix.com> wrote:

How can i make these "invisible" characters visible?

In psql, by default it displays nulls as nothing. You can specify what
they should display as with:

\pset null '<something>'

Chances are those are all nulls, and will now display as whatever you set
them to. If they aren't, let us know.

#3stan
stanb@panix.com
In reply to: Brian Dunavant (#2)
Re: Making "invisible" characters visible ? (psql)

On Wed, Nov 20, 2019 at 09:22:02AM -0500, Brian Dunavant wrote:

On Wed, Nov 20, 2019 at 9:16 AM stan <stanb@panix.com> wrote:

How can i make these "invisible" characters visible?

In psql, by default it displays nulls as nothing. You can specify what
they should display as with:

\pset null '<something>'

Chances are those are all nulls, and will now display as whatever you set
them to. If they aren't, let us know.

That worked, and yes they are NULLs, guess I expected to get 0 rows, as the
only column I requested contained ONLY NULL's.

basic misunderstanding on my part, i suppose.

Thank you for your help.

--
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
-- Benjamin Franklin

#4Adrian Klaver
adrian.klaver@aklaver.com
In reply to: stan (#3)
Re: Making "invisible" characters visible ? (psql)

On 11/20/19 7:01 AM, stan wrote:

On Wed, Nov 20, 2019 at 09:22:02AM -0500, Brian Dunavant wrote:

On Wed, Nov 20, 2019 at 9:16 AM stan <stanb@panix.com> wrote:

How can i make these "invisible" characters visible?

In psql, by default it displays nulls as nothing. You can specify what
they should display as with:

\pset null '<something>'

Chances are those are all nulls, and will now display as whatever you set
them to. If they aren't, let us know.

That worked, and yes they are NULLs, guess I expected to get 0 rows, as the
only column I requested contained ONLY NULL's.

basic misunderstanding on my part, i suppose.

NULL is a value so it should 'show' up.

Thank you for your help.

--
Adrian Klaver
adrian.klaver@aklaver.com