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distinct aggregate with complex type dont see the equality operator
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* distinct aggregate with complex type dont see the equality operator
@ 2006-05-29 20:14 Thomas Chille <thomas@chille.de>
  0 siblings, 0 replies; 2+ messages in thread

From: Thomas Chille @ 2006-05-29 20:14 UTC (permalink / raw)
  To: pgsql-sql

Dear List,

i want to built an aggregate function wich should summing up values in
a distinct manner:

dsum(DISTINCT ROW(value, distinction)).

I implemented all things i thought i need but it dont work. i get
always an 'could not identify an equality operator for type
dsum_type'-error nevertheless the operator will be identified outside
the aggregate.

Here is the code for the equality operator:

CREATE OR REPLACE FUNCTION dsum_type_greater(dsum_type, dsum_type)
RETURNS boolean AS $f$
    SELECT $1.distinction > $2.distinction;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OPERATOR = (
    PROCEDURE = dsum_type_equality,
    LEFTARG = dsum_type,
    RIGHTARG = dsum_type,
    COMMUTATOR = =
);

And this happens:

-- result is FALSE
SELECT ROW(5, 'foo')::dsum_type = ROW(5, 'bar')::dsum_type;

-- result is TRUE
SELECT ROW(5, 'foo')::dsum_type = ROW(5, 'foo')::dsum_type;

-- result is TRUE
SELECT ROW(4, 'foo')::dsum_type = ROW(5, 'foo')::dsum_type;

-- works for me
SELECT dsum(ROW(wert, name)::dsum_type) FROM table1;

-- ERROR: could not identify an equality operator for type dsum_type
SELECT dsum(DISTINCT ROW(wert, name)::dsum_type) FROM table1;

i added the less then and greater then ops too, but it still wont work.

What i am doing wrong or can i achieve the wished result without
usinge a comlex type?

regards,
Thomas!



^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* Re: distinct aggregate with complex type dont see the equality operator [solved]
@ 2006-06-01 14:21 Thomas Chille <thomas@chille.de>
  0 siblings, 0 replies; 2+ messages in thread

From: Thomas Chille @ 2006-06-01 14:21 UTC (permalink / raw)
  To: pgsql-sql

using DISTINCT with complex types depends on an OPERATOR CLASS for
B-Tree-Indexes i found out. the error msg 'could not identify an
equality operator for type' was confusing.

i post this complete example. maybe someone else is running in this problem too.

regards,
thomas!



CREATE TYPE named_value AS (
    value_name text,
    value numeric
);

CREATE OR REPLACE FUNCTION named_value_lt(named_value, named_value)
RETURNS boolean AS $f$
    SELECT $1.value_name < $2.value_name;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION named_value_lt_eq(named_value, named_value)
RETURNS boolean AS $f$
    SELECT $1.value_name <= $2.value_name;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION named_value_eq(named_value, named_value)
RETURNS boolean AS $f$
    SELECT $1.value_name = $2.value_name;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION named_value_gt_eq(named_value, named_value)
RETURNS boolean AS $f$
    SELECT $1.value_name >= $2.value_name;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION named_value_gt(named_value, named_value)
RETURNS boolean AS $f$
    SELECT $1.value_name > $2.value_name;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION named_value_cmp(named_value, named_value)
RETURNS integer AS $f$
    SELECT CASE
        WHEN $1.value_name < $2.value_name THEN -1
        WHEN $1.value_name = $2.value_name THEN 0
        ELSE 1
    END;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OPERATOR < (
    PROCEDURE = named_value_lt,
    LEFTARG = named_value,
    RIGHTARG = named_value,
    COMMUTATOR = >
);

CREATE OPERATOR <= (
    PROCEDURE = named_value_lt_eq,
    LEFTARG = named_value,
    RIGHTARG = named_value,
    COMMUTATOR = >=
);

CREATE OPERATOR = (
    PROCEDURE = named_value_eq,
    LEFTARG = named_value,
    RIGHTARG = named_value,
    COMMUTATOR = =
);

CREATE OPERATOR >= (
    PROCEDURE = named_value_gt_eq,
    LEFTARG = named_value,
    RIGHTARG = named_value,
    COMMUTATOR = <=
);

CREATE OPERATOR > (
    PROCEDURE = named_value_gt,
    LEFTARG = named_value,
    RIGHTARG = named_value,
    COMMUTATOR = <
);

CREATE OPERATOR CLASS named_value_ops
    DEFAULT FOR TYPE named_value USING btree AS
        OPERATOR    1    < ,
        OPERATOR    2    <= ,
        OPERATOR    3    = ,
        OPERATOR    4    >= ,
        OPERATOR    5    > ,
        FUNCTION    1    named_value_cmp(named_value, named_value);


CREATE OR REPLACE FUNCTION sum_final(named_value)
RETURNS numeric AS $f$
    SELECT $1.value;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION sum_accum(named_value, named_value)
RETURNS named_value AS $f$
    SELECT ROW('', $1.value + $2.value)::named_value;
$f$ LANGUAGE sql IMMUTABLE STRICT;

CREATE AGGREGATE sum(
     BASETYPE = named_value,
     SFUNC = sum_accum,
     STYPE = named_value,
     FINALFUNC = sum_final,
     INITCOND = "('',0)"
);
-- result is FALSE
SELECT ROW('foo', 5)::named_value = ROW('bar', 5)::named_value;

-- result is TRUE
SELECT ROW('foo', 5)::named_value = ROW('foo', 5)::named_value;

-- result is TRUE
SELECT ROW('foo', 4)::named_value = ROW('foo', 5)::named_value;

-- works for me
SELECT sum(ROW(name, wert)::named_value) FROM table1;

-- now works for me too
SELECT DISTINCT ROW(wert, name)::named_value FROM table1;
SELECT sum(DISTINCT ROW(name, wert)::named_value) FROM table1;



^ permalink  raw  reply  [nested|flat] 2+ messages in thread

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2006-05-29 20:14 distinct aggregate with complex type dont see the equality operator Thomas Chille <thomas@chille.de>
2006-06-01 14:21 Re: distinct aggregate with complex type dont see the equality operator [solved] Thomas Chille <thomas@chille.de>

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