104 lines
3.6 KiB
Plaintext
104 lines
3.6 KiB
Plaintext
--
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-- CREATE_CAST
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--
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-- Create some types to test with
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CREATE TYPE casttesttype;
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CREATE FUNCTION casttesttype_in(cstring)
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RETURNS casttesttype
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AS 'textin'
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LANGUAGE internal STRICT IMMUTABLE;
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NOTICE: return type casttesttype is only a shell
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CREATE FUNCTION casttesttype_out(casttesttype)
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RETURNS cstring
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AS 'textout'
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LANGUAGE internal STRICT IMMUTABLE;
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NOTICE: argument type casttesttype is only a shell
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CREATE TYPE casttesttype (
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internallength = variable,
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input = casttesttype_in,
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output = casttesttype_out,
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alignment = int4
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);
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-- a dummy function to test with
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CREATE FUNCTION casttestfunc(casttesttype) RETURNS int4 LANGUAGE SQL AS
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$$ SELECT 1; $$;
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SELECT casttestfunc('foo'::text); -- fails, as there's no cast
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ERROR: function casttestfunc(text) does not exist
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LINE 1: SELECT casttestfunc('foo'::text);
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^
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HINT: No function matches the given name and argument types. You might need to add explicit type casts.
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-- Try binary coercion cast
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CREATE CAST (text AS casttesttype) WITHOUT FUNCTION;
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SELECT casttestfunc('foo'::text); -- doesn't work, as the cast is explicit
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ERROR: function casttestfunc(text) does not exist
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LINE 1: SELECT casttestfunc('foo'::text);
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^
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HINT: No function matches the given name and argument types. You might need to add explicit type casts.
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SELECT casttestfunc('foo'::text::casttesttype); -- should work
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casttestfunc
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--------------
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1
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(1 row)
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DROP CAST (text AS casttesttype); -- cleanup
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-- Try IMPLICIT binary coercion cast
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CREATE CAST (text AS casttesttype) WITHOUT FUNCTION AS IMPLICIT;
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SELECT casttestfunc('foo'::text); -- Should work now
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casttestfunc
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--------------
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1
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(1 row)
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-- Try I/O conversion cast.
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SELECT 1234::int4::casttesttype; -- No cast yet, should fail
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ERROR: cannot cast type integer to casttesttype
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LINE 1: SELECT 1234::int4::casttesttype;
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^
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CREATE CAST (int4 AS casttesttype) WITH INOUT;
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SELECT 1234::int4::casttesttype; -- Should work now
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casttesttype
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--------------
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1234
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(1 row)
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DROP CAST (int4 AS casttesttype);
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-- Try cast with a function
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CREATE FUNCTION int4_casttesttype(int4) RETURNS casttesttype LANGUAGE SQL AS
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$$ SELECT ('foo'::text || $1::text)::casttesttype; $$;
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CREATE CAST (int4 AS casttesttype) WITH FUNCTION int4_casttesttype(int4) AS IMPLICIT;
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SELECT 1234::int4::casttesttype; -- Should work now
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casttesttype
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--------------
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foo1234
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(1 row)
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DROP FUNCTION int4_casttesttype(int4) CASCADE;
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NOTICE: drop cascades to cast from integer to casttesttype
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-- Try it with a function that requires an implicit cast
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CREATE FUNCTION bar_int4_text(int4) RETURNS text LANGUAGE SQL AS
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$$ SELECT ('bar'::text || $1::text); $$;
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CREATE CAST (int4 AS casttesttype) WITH FUNCTION bar_int4_text(int4) AS IMPLICIT;
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SELECT 1234::int4::casttesttype; -- Should work now
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casttesttype
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--------------
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bar1234
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(1 row)
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-- check dependencies generated for that
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SELECT pg_describe_object(classid, objid, objsubid) as obj,
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pg_describe_object(refclassid, refobjid, refobjsubid) as objref,
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deptype
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FROM pg_depend
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WHERE classid = 'pg_cast'::regclass AND
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objid = (SELECT oid FROM pg_cast
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WHERE castsource = 'int4'::regtype
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AND casttarget = 'casttesttype'::regtype)
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ORDER BY refclassid;
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obj | objref | deptype
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-----------------------------------+---------------------------------+---------
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cast from integer to casttesttype | type casttesttype | n
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cast from integer to casttesttype | function bar_int4_text(integer) | n
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cast from integer to casttesttype | cast from text to casttesttype | n
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(3 rows)
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