A console session to illustrate the problem follows below. Note that the documentation says: <p>
"The columns object command allows the program to query the connection for the names of columns that exist in a <b>given</b> table."
<p>In Postgres you identify tables by a fully qualified name, using the following name convention:
<schema name>.<table name>
<p><hr>
Main console display active (Tcl8.6.4 / Tk8.6.4)<p>
(System32) 49 % package require tdbc::postgres<p>
<i>1.0.0</i><p>
(System32) 50 % tdbc::postgres::connection create db -user postgres -password postgres -db mydb<p>
<i>::db</i><p>
(System32) 51 % db allrows {create schema myschema}<p>
(System32) 52 % db allrows {create table myschema.mytable (id serial primary key, field1 text)}<p>
(System32) 53 % db columns myschema.mytable field1<p>
(System32) 54 % db columns mytable field1<p>
<i>relation "mytable" does not exist</i><p>
(System32) 55 % db allrows {set search_path=myschema,public}<p>
(System32) 56 % db columns mytable field1<p>
<i>field1 {name field1 type text nullable 1}<i><p>
(System32) 57 % <p>