Re: [SQL] distinct aggregate with complex type dont see the equality operator [solved]

[Thomas Chille]

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;

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