2014-09-04 11:13 GMT+02:00 Vinayak <vinpok...@gmail.com>: > Hi, > > The || operator with arguments (character,character) works fine and even || > operator(character,varchar) also works fine. > but || operator is not working as expected with arguments character data > type and any other data type like integer,smallint,date,text. > Example: > postgres=# select 'ab'::char(10) || 4::int; > ?column? > ---------- > ab4 > (1 row) > postgres=# select 'ab'::char(10) || 'a'::text; > ?column? > ------------- > aba > (1 row) > > so I have created || operator with argument character and anyelement. > Example: > create or replace function concat_character(character, anyelement) returns > text as $$ select concat($1,$2)$$ language sql; > create operator || (procedure = concat_character, leftarg = character, > rightarg = anyelement); > it works fine with argument of type int,smallint,bigint,date etc. > but its not working with text and varchar data type. > Example: > postgres=# select 'ab'::char(10) || 4::int; > ?column? > ------------- > ab 4 > (1 row) > > postgres=# select 'ab'::char(10) || 'b'::text; > ?column? > ---------- > abb > (1 row) >
text is more general -- it it does cast to text - there is not || operator for leftarg character and righarg text > > postgres=# select 'ab'::char(10) || 'b'::varchar(5); > ERROR: operator is not unique: character || character varying > LINE 1: select 'ab'::char(10) || 'b'::varchar(5); > ^ > HINT: Could not choose a best candidate operator. You might need to add > explicit type casts. > Thought? > > Not too much - it is limit of Postgres type system :( Pavel > > ----- > Regards, > Vinayak, > > -- > View this message in context: > http://postgresql.1045698.n5.nabble.com/operator-tp5817541p5817712.html > Sent from the PostgreSQL - general mailing list archive at Nabble.com. > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >
