Hi,
I have three tables, two of which are missing a column:
CREATE TABLE table1 (t1 TEXT);CREATE TABLE table2 (t2 TEXT);CREATE TABLE table3 (t3 TEXT, i3 INTEGER);
I am trying to create a view over these tables that defaults values for
non-existant columns to NULL.
CREATE VIEW view1 (i, t) AS SELECT t1, NULL FROM table1 UNION ALL SELECT t2, NULL FROM table2 UNION ALL SELECT
t3,i3 FROM table3;
This fails with
ERROR: UNION types 'text' and 'integer' not matched
suggesting that NULL+NULL produces TEXT as type of the second column in
the union. The plain select (without CREATE VIEW) fails in the same way.
It works for two tables (NULL+INTEGER = INTEGER):
CREATE VIEW view2 (i, t) AS SELECT t1, NULL FROM table1 UNION ALL SELECT t3, i3 FROM table3;
and of course with explicit casts
CREATE VIEW view3 (i, t) AS SELECT t1, NULL::integer FROM table1UNION ALL SELECT t2, NULL::integer FROM table2UNION
ALL SELECT t3, i3 FROM table3;
Best wishes, Mike
PS: This is version() 'PostgreSQL 7.3.1 on i686-pc-linux-gnu, compiled by GCC 2.95.4'.
--
Life is like a fire. DI Michael Wildpaner
Flames which the passer-by forgets. Ph.D. Student
Ashes which the wind scatters.
A man lived. -- Omar Khayyam