1 /*-------------------------------------------------------------------------
4 * Utility and convenience functions for fmgr functions that return
5 * sets and/or composite types.
7 * Copyright (c) 2002-2010, PostgreSQL Global Development Group
10 * $PostgreSQL: pgsql/src/backend/utils/fmgr/funcapi.c,v 1.49 2010/02/26 02:01:13 momjian Exp $
12 *-------------------------------------------------------------------------
16 #include "access/heapam.h"
17 #include "catalog/namespace.h"
18 #include "catalog/pg_proc.h"
19 #include "catalog/pg_type.h"
21 #include "nodes/nodeFuncs.h"
22 #include "parser/parse_coerce.h"
23 #include "utils/array.h"
24 #include "utils/builtins.h"
25 #include "utils/lsyscache.h"
26 #include "utils/memutils.h"
27 #include "utils/syscache.h"
28 #include "utils/typcache.h"
31 static void shutdown_MultiFuncCall(Datum arg);
32 static TypeFuncClass internal_get_result_type(Oid funcid,
34 ReturnSetInfo *rsinfo,
36 TupleDesc *resultTupleDesc);
37 static bool resolve_polymorphic_tupdesc(TupleDesc tupdesc,
38 oidvector *declared_args,
40 static TypeFuncClass get_type_func_class(Oid typid);
45 * Create an empty FuncCallContext data structure
46 * and do some other basic Multi-function call setup
50 init_MultiFuncCall(PG_FUNCTION_ARGS)
52 FuncCallContext *retval;
55 * Bail if we're called in the wrong context
57 if (fcinfo->resultinfo == NULL || !IsA(fcinfo->resultinfo, ReturnSetInfo))
59 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
60 errmsg("set-valued function called in context that cannot accept a set")));
62 if (fcinfo->flinfo->fn_extra == NULL)
67 ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
68 MemoryContext multi_call_ctx;
71 * Create a suitably long-lived context to hold cross-call data
73 multi_call_ctx = AllocSetContextCreate(fcinfo->flinfo->fn_mcxt,
74 "SRF multi-call context",
75 ALLOCSET_SMALL_MINSIZE,
76 ALLOCSET_SMALL_INITSIZE,
77 ALLOCSET_SMALL_MAXSIZE);
80 * Allocate suitably long-lived space and zero it
82 retval = (FuncCallContext *)
83 MemoryContextAllocZero(multi_call_ctx,
84 sizeof(FuncCallContext));
87 * initialize the elements
89 retval->call_cntr = 0;
90 retval->max_calls = 0;
92 retval->user_fctx = NULL;
93 retval->attinmeta = NULL;
94 retval->tuple_desc = NULL;
95 retval->multi_call_memory_ctx = multi_call_ctx;
98 * save the pointer for cross-call use
100 fcinfo->flinfo->fn_extra = retval;
103 * Ensure we will get shut down cleanly if the exprcontext is not run
106 RegisterExprContextCallback(rsi->econtext,
107 shutdown_MultiFuncCall,
108 PointerGetDatum(fcinfo->flinfo));
112 /* second and subsequent calls */
113 elog(ERROR, "init_MultiFuncCall cannot be called more than once");
115 /* never reached, but keep compiler happy */
125 * Do Multi-function per-call setup
128 per_MultiFuncCall(PG_FUNCTION_ARGS)
130 FuncCallContext *retval = (FuncCallContext *) fcinfo->flinfo->fn_extra;
133 * Clear the TupleTableSlot, if present. This is for safety's sake: the
134 * Slot will be in a long-lived context (it better be, if the
135 * FuncCallContext is pointing to it), but in most usage patterns the
136 * tuples stored in it will be in the function's per-tuple context. So at
137 * the beginning of each call, the Slot will hold a dangling pointer to an
138 * already-recycled tuple. We clear it out here.
140 * Note: use of retval->slot is obsolete as of 8.0, and we expect that it
141 * will always be NULL. This is just here for backwards compatibility in
142 * case someone creates a slot anyway.
144 if (retval->slot != NULL)
145 ExecClearTuple(retval->slot);
152 * Clean up after init_MultiFuncCall
155 end_MultiFuncCall(PG_FUNCTION_ARGS, FuncCallContext *funcctx)
157 ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
159 /* Deregister the shutdown callback */
160 UnregisterExprContextCallback(rsi->econtext,
161 shutdown_MultiFuncCall,
162 PointerGetDatum(fcinfo->flinfo));
164 /* But use it to do the real work */
165 shutdown_MultiFuncCall(PointerGetDatum(fcinfo->flinfo));
169 * shutdown_MultiFuncCall
170 * Shutdown function to clean up after init_MultiFuncCall
173 shutdown_MultiFuncCall(Datum arg)
175 FmgrInfo *flinfo = (FmgrInfo *) DatumGetPointer(arg);
176 FuncCallContext *funcctx = (FuncCallContext *) flinfo->fn_extra;
178 /* unbind from flinfo */
179 flinfo->fn_extra = NULL;
182 * Delete context that holds all multi-call data, including the
183 * FuncCallContext itself
185 MemoryContextDelete(funcctx->multi_call_memory_ctx);
190 * get_call_result_type
191 * Given a function's call info record, determine the kind of datatype
192 * it is supposed to return. If resultTypeId isn't NULL, *resultTypeId
193 * receives the actual datatype OID (this is mainly useful for scalar
194 * result types). If resultTupleDesc isn't NULL, *resultTupleDesc
195 * receives a pointer to a TupleDesc when the result is of a composite
196 * type, or NULL when it's a scalar result.
198 * One hard case that this handles is resolution of actual rowtypes for
199 * functions returning RECORD (from either the function's OUT parameter
200 * list, or a ReturnSetInfo context node). TYPEFUNC_RECORD is returned
201 * only when we couldn't resolve the actual rowtype for lack of information.
203 * The other hard case that this handles is resolution of polymorphism.
204 * We will never return polymorphic pseudotypes (ANYELEMENT etc), either
205 * as a scalar result type or as a component of a rowtype.
207 * This function is relatively expensive --- in a function returning set,
208 * try to call it only the first time through.
211 get_call_result_type(FunctionCallInfo fcinfo,
213 TupleDesc *resultTupleDesc)
215 return internal_get_result_type(fcinfo->flinfo->fn_oid,
216 fcinfo->flinfo->fn_expr,
217 (ReturnSetInfo *) fcinfo->resultinfo,
223 * get_expr_result_type
224 * As above, but work from a calling expression node tree
227 get_expr_result_type(Node *expr,
229 TupleDesc *resultTupleDesc)
231 TypeFuncClass result;
233 if (expr && IsA(expr, FuncExpr))
234 result = internal_get_result_type(((FuncExpr *) expr)->funcid,
239 else if (expr && IsA(expr, OpExpr))
240 result = internal_get_result_type(get_opcode(((OpExpr *) expr)->opno),
247 /* handle as a generic expression; no chance to resolve RECORD */
248 Oid typid = exprType(expr);
251 *resultTypeId = typid;
253 *resultTupleDesc = NULL;
254 result = get_type_func_class(typid);
255 if (result == TYPEFUNC_COMPOSITE && resultTupleDesc)
256 *resultTupleDesc = lookup_rowtype_tupdesc_copy(typid, -1);
263 * get_func_result_type
264 * As above, but work from a function's OID only
266 * This will not be able to resolve pure-RECORD results nor polymorphism.
269 get_func_result_type(Oid functionId,
271 TupleDesc *resultTupleDesc)
273 return internal_get_result_type(functionId,
281 * internal_get_result_type -- workhorse code implementing all the above
283 * funcid must always be supplied. call_expr and rsinfo can be NULL if not
284 * available. We will return TYPEFUNC_RECORD, and store NULL into
285 * *resultTupleDesc, if we cannot deduce the complete result rowtype from
286 * the available information.
289 internal_get_result_type(Oid funcid,
291 ReturnSetInfo *rsinfo,
293 TupleDesc *resultTupleDesc)
295 TypeFuncClass result;
297 Form_pg_proc procform;
301 /* First fetch the function's pg_proc row to inspect its rettype */
302 tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
303 if (!HeapTupleIsValid(tp))
304 elog(ERROR, "cache lookup failed for function %u", funcid);
305 procform = (Form_pg_proc) GETSTRUCT(tp);
307 rettype = procform->prorettype;
309 /* Check for OUT parameters defining a RECORD result */
310 tupdesc = build_function_result_tupdesc_t(tp);
314 * It has OUT parameters, so it's basically like a regular composite
315 * type, except we have to be able to resolve any polymorphic OUT
319 *resultTypeId = rettype;
321 if (resolve_polymorphic_tupdesc(tupdesc,
322 &procform->proargtypes,
325 if (tupdesc->tdtypeid == RECORDOID &&
326 tupdesc->tdtypmod < 0)
327 assign_record_type_typmod(tupdesc);
329 *resultTupleDesc = tupdesc;
330 result = TYPEFUNC_COMPOSITE;
335 *resultTupleDesc = NULL;
336 result = TYPEFUNC_RECORD;
345 * If scalar polymorphic result, try to resolve it.
347 if (IsPolymorphicType(rettype))
349 Oid newrettype = exprType(call_expr);
351 if (newrettype == InvalidOid) /* this probably should not happen */
353 (errcode(ERRCODE_DATATYPE_MISMATCH),
354 errmsg("could not determine actual result type for function \"%s\" declared to return type %s",
355 NameStr(procform->proname),
356 format_type_be(rettype))));
357 rettype = newrettype;
361 *resultTypeId = rettype;
363 *resultTupleDesc = NULL; /* default result */
365 /* Classify the result type */
366 result = get_type_func_class(rettype);
369 case TYPEFUNC_COMPOSITE:
371 *resultTupleDesc = lookup_rowtype_tupdesc_copy(rettype, -1);
372 /* Named composite types can't have any polymorphic columns */
374 case TYPEFUNC_SCALAR:
376 case TYPEFUNC_RECORD:
377 /* We must get the tupledesc from call context */
378 if (rsinfo && IsA(rsinfo, ReturnSetInfo) &&
379 rsinfo->expectedDesc != NULL)
381 result = TYPEFUNC_COMPOSITE;
383 *resultTupleDesc = rsinfo->expectedDesc;
384 /* Assume no polymorphic columns here, either */
397 * Given the result tuple descriptor for a function with OUT parameters,
398 * replace any polymorphic columns (ANYELEMENT etc) with correct data types
399 * deduced from the input arguments. Returns TRUE if able to deduce all types,
403 resolve_polymorphic_tupdesc(TupleDesc tupdesc, oidvector *declared_args,
406 int natts = tupdesc->natts;
407 int nargs = declared_args->dim1;
408 bool have_anyelement_result = false;
409 bool have_anyarray_result = false;
410 bool have_anynonarray = false;
411 bool have_anyenum = false;
412 Oid anyelement_type = InvalidOid;
413 Oid anyarray_type = InvalidOid;
416 /* See if there are any polymorphic outputs; quick out if not */
417 for (i = 0; i < natts; i++)
419 switch (tupdesc->attrs[i]->atttypid)
422 have_anyelement_result = true;
425 have_anyarray_result = true;
428 have_anyelement_result = true;
429 have_anynonarray = true;
432 have_anyelement_result = true;
439 if (!have_anyelement_result && !have_anyarray_result)
443 * Otherwise, extract actual datatype(s) from input arguments. (We assume
444 * the parser already validated consistency of the arguments.)
447 return false; /* no hope */
449 for (i = 0; i < nargs; i++)
451 switch (declared_args->values[i])
456 if (!OidIsValid(anyelement_type))
457 anyelement_type = get_call_expr_argtype(call_expr, i);
460 if (!OidIsValid(anyarray_type))
461 anyarray_type = get_call_expr_argtype(call_expr, i);
468 /* If nothing found, parser messed up */
469 if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type))
472 /* If needed, deduce one polymorphic type from the other */
473 if (have_anyelement_result && !OidIsValid(anyelement_type))
474 anyelement_type = resolve_generic_type(ANYELEMENTOID,
477 if (have_anyarray_result && !OidIsValid(anyarray_type))
478 anyarray_type = resolve_generic_type(ANYARRAYOID,
482 /* Enforce ANYNONARRAY if needed */
483 if (have_anynonarray && type_is_array(anyelement_type))
486 /* Enforce ANYENUM if needed */
487 if (have_anyenum && !type_is_enum(anyelement_type))
490 /* And finally replace the tuple column types as needed */
491 for (i = 0; i < natts; i++)
493 switch (tupdesc->attrs[i]->atttypid)
498 TupleDescInitEntry(tupdesc, i + 1,
499 NameStr(tupdesc->attrs[i]->attname),
505 TupleDescInitEntry(tupdesc, i + 1,
506 NameStr(tupdesc->attrs[i]->attname),
520 * Given the declared argument types and modes for a function, replace any
521 * polymorphic types (ANYELEMENT etc) with correct data types deduced from the
522 * input arguments. Returns TRUE if able to deduce all types, FALSE if not.
523 * This is the same logic as resolve_polymorphic_tupdesc, but with a different
524 * argument representation.
526 * argmodes may be NULL, in which case all arguments are assumed to be IN mode.
529 resolve_polymorphic_argtypes(int numargs, Oid *argtypes, char *argmodes,
532 bool have_anyelement_result = false;
533 bool have_anyarray_result = false;
534 Oid anyelement_type = InvalidOid;
535 Oid anyarray_type = InvalidOid;
539 /* First pass: resolve polymorphic inputs, check for outputs */
541 for (i = 0; i < numargs; i++)
543 char argmode = argmodes ? argmodes[i] : PROARGMODE_IN;
550 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
551 have_anyelement_result = true;
554 if (!OidIsValid(anyelement_type))
556 anyelement_type = get_call_expr_argtype(call_expr,
558 if (!OidIsValid(anyelement_type))
561 argtypes[i] = anyelement_type;
565 if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
566 have_anyarray_result = true;
569 if (!OidIsValid(anyarray_type))
571 anyarray_type = get_call_expr_argtype(call_expr,
573 if (!OidIsValid(anyarray_type))
576 argtypes[i] = anyarray_type;
582 if (argmode != PROARGMODE_OUT && argmode != PROARGMODE_TABLE)
587 if (!have_anyelement_result && !have_anyarray_result)
590 /* If no input polymorphics, parser messed up */
591 if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type))
594 /* If needed, deduce one polymorphic type from the other */
595 if (have_anyelement_result && !OidIsValid(anyelement_type))
596 anyelement_type = resolve_generic_type(ANYELEMENTOID,
599 if (have_anyarray_result && !OidIsValid(anyarray_type))
600 anyarray_type = resolve_generic_type(ANYARRAYOID,
604 /* XXX do we need to enforce ANYNONARRAY or ANYENUM here? I think not */
606 /* And finally replace the output column types as needed */
607 for (i = 0; i < numargs; i++)
614 argtypes[i] = anyelement_type;
617 argtypes[i] = anyarray_type;
628 * get_type_func_class
629 * Given the type OID, obtain its TYPEFUNC classification.
631 * This is intended to centralize a bunch of formerly ad-hoc code for
632 * classifying types. The categories used here are useful for deciding
633 * how to handle functions returning the datatype.
636 get_type_func_class(Oid typid)
638 switch (get_typtype(typid))
640 case TYPTYPE_COMPOSITE:
641 return TYPEFUNC_COMPOSITE;
645 return TYPEFUNC_SCALAR;
647 if (typid == RECORDOID)
648 return TYPEFUNC_RECORD;
651 * We treat VOID and CSTRING as legitimate scalar datatypes,
652 * mostly for the convenience of the JDBC driver (which wants to
653 * be able to do "SELECT * FROM foo()" for all legitimately
654 * user-callable functions).
656 if (typid == VOIDOID || typid == CSTRINGOID)
657 return TYPEFUNC_SCALAR;
658 return TYPEFUNC_OTHER;
660 /* shouldn't get here, probably */
661 return TYPEFUNC_OTHER;
668 * Fetch info about the argument types, names, and IN/OUT modes from the
669 * pg_proc tuple. Return value is the total number of arguments.
670 * Other results are palloc'd. *p_argtypes is always filled in, but
671 * *p_argnames and *p_argmodes will be set NULL in the default cases
672 * (no names, and all IN arguments, respectively).
674 * Note that this function simply fetches what is in the pg_proc tuple;
675 * it doesn't do any interpretation of polymorphic types.
678 get_func_arg_info(HeapTuple procTup,
679 Oid **p_argtypes, char ***p_argnames, char **p_argmodes)
681 Form_pg_proc procStruct = (Form_pg_proc) GETSTRUCT(procTup);
682 Datum proallargtypes;
692 /* First discover the total number of parameters and get their types */
693 proallargtypes = SysCacheGetAttr(PROCOID, procTup,
694 Anum_pg_proc_proallargtypes,
699 * We expect the arrays to be 1-D arrays of the right types; verify
700 * that. For the OID and char arrays, we don't need to use
701 * deconstruct_array() since the array data is just going to look like
702 * a C array of values.
704 arr = DatumGetArrayTypeP(proallargtypes); /* ensure not toasted */
705 numargs = ARR_DIMS(arr)[0];
706 if (ARR_NDIM(arr) != 1 ||
709 ARR_ELEMTYPE(arr) != OIDOID)
710 elog(ERROR, "proallargtypes is not a 1-D Oid array");
711 Assert(numargs >= procStruct->pronargs);
712 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
713 memcpy(*p_argtypes, ARR_DATA_PTR(arr),
714 numargs * sizeof(Oid));
718 /* If no proallargtypes, use proargtypes */
719 numargs = procStruct->proargtypes.dim1;
720 Assert(numargs == procStruct->pronargs);
721 *p_argtypes = (Oid *) palloc(numargs * sizeof(Oid));
722 memcpy(*p_argtypes, procStruct->proargtypes.values,
723 numargs * sizeof(Oid));
726 /* Get argument names, if available */
727 proargnames = SysCacheGetAttr(PROCOID, procTup,
728 Anum_pg_proc_proargnames,
734 deconstruct_array(DatumGetArrayTypeP(proargnames),
735 TEXTOID, -1, false, 'i',
736 &elems, NULL, &nelems);
737 if (nelems != numargs) /* should not happen */
738 elog(ERROR, "proargnames must have the same number of elements as the function has arguments");
739 *p_argnames = (char **) palloc(sizeof(char *) * numargs);
740 for (i = 0; i < numargs; i++)
741 (*p_argnames)[i] = TextDatumGetCString(elems[i]);
744 /* Get argument modes, if available */
745 proargmodes = SysCacheGetAttr(PROCOID, procTup,
746 Anum_pg_proc_proargmodes,
752 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
753 if (ARR_NDIM(arr) != 1 ||
754 ARR_DIMS(arr)[0] != numargs ||
756 ARR_ELEMTYPE(arr) != CHAROID)
757 elog(ERROR, "proargmodes is not a 1-D char array");
758 *p_argmodes = (char *) palloc(numargs * sizeof(char));
759 memcpy(*p_argmodes, ARR_DATA_PTR(arr),
760 numargs * sizeof(char));
768 * get_func_input_arg_names
770 * Extract the names of input arguments only, given a function's
771 * proargnames and proargmodes entries in Datum form.
773 * Returns the number of input arguments, which is the length of the
774 * palloc'd array returned to *arg_names. Entries for unnamed args
775 * are set to NULL. You don't get anything if proargnames is NULL.
778 get_func_input_arg_names(Datum proargnames, Datum proargmodes,
789 /* Do nothing if null proargnames */
790 if (proargnames == PointerGetDatum(NULL))
797 * We expect the arrays to be 1-D arrays of the right types; verify that.
798 * For proargmodes, we don't need to use deconstruct_array() since the
799 * array data is just going to look like a C array of values.
801 arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
802 if (ARR_NDIM(arr) != 1 ||
804 ARR_ELEMTYPE(arr) != TEXTOID)
805 elog(ERROR, "proargnames is not a 1-D text array");
806 deconstruct_array(arr, TEXTOID, -1, false, 'i',
807 &argnames, NULL, &numargs);
808 if (proargmodes != PointerGetDatum(NULL))
810 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
811 if (ARR_NDIM(arr) != 1 ||
812 ARR_DIMS(arr)[0] != numargs ||
814 ARR_ELEMTYPE(arr) != CHAROID)
815 elog(ERROR, "proargmodes is not a 1-D char array");
816 argmodes = (char *) ARR_DATA_PTR(arr);
821 /* zero elements probably shouldn't happen, but handle it gracefully */
828 /* extract input-argument names */
829 inargnames = (char **) palloc(numargs * sizeof(char *));
831 for (i = 0; i < numargs; i++)
833 if (argmodes == NULL ||
834 argmodes[i] == PROARGMODE_IN ||
835 argmodes[i] == PROARGMODE_INOUT ||
836 argmodes[i] == PROARGMODE_VARIADIC)
838 char *pname = TextDatumGetCString(argnames[i]);
840 if (pname[0] != '\0')
841 inargnames[numinargs] = pname;
843 inargnames[numinargs] = NULL;
848 *arg_names = inargnames;
854 * get_func_result_name
856 * If the function has exactly one output parameter, and that parameter
857 * is named, return the name (as a palloc'd string). Else return NULL.
859 * This is used to determine the default output column name for functions
860 * returning scalar types.
863 get_func_result_name(Oid functionId)
878 /* First fetch the function's pg_proc row */
879 procTuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(functionId));
880 if (!HeapTupleIsValid(procTuple))
881 elog(ERROR, "cache lookup failed for function %u", functionId);
883 /* If there are no named OUT parameters, return NULL */
884 if (heap_attisnull(procTuple, Anum_pg_proc_proargmodes) ||
885 heap_attisnull(procTuple, Anum_pg_proc_proargnames))
889 /* Get the data out of the tuple */
890 proargmodes = SysCacheGetAttr(PROCOID, procTuple,
891 Anum_pg_proc_proargmodes,
894 proargnames = SysCacheGetAttr(PROCOID, procTuple,
895 Anum_pg_proc_proargnames,
900 * We expect the arrays to be 1-D arrays of the right types; verify
901 * that. For the char array, we don't need to use deconstruct_array()
902 * since the array data is just going to look like a C array of
905 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
906 numargs = ARR_DIMS(arr)[0];
907 if (ARR_NDIM(arr) != 1 ||
910 ARR_ELEMTYPE(arr) != CHAROID)
911 elog(ERROR, "proargmodes is not a 1-D char array");
912 argmodes = (char *) ARR_DATA_PTR(arr);
913 arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
914 if (ARR_NDIM(arr) != 1 ||
915 ARR_DIMS(arr)[0] != numargs ||
917 ARR_ELEMTYPE(arr) != TEXTOID)
918 elog(ERROR, "proargnames is not a 1-D text array");
919 deconstruct_array(arr, TEXTOID, -1, false, 'i',
920 &argnames, NULL, &nargnames);
921 Assert(nargnames == numargs);
923 /* scan for output argument(s) */
926 for (i = 0; i < numargs; i++)
928 if (argmodes[i] == PROARGMODE_IN ||
929 argmodes[i] == PROARGMODE_VARIADIC)
931 Assert(argmodes[i] == PROARGMODE_OUT ||
932 argmodes[i] == PROARGMODE_INOUT ||
933 argmodes[i] == PROARGMODE_TABLE);
934 if (++numoutargs > 1)
936 /* multiple out args, so forget it */
940 result = TextDatumGetCString(argnames[i]);
941 if (result == NULL || result[0] == '\0')
943 /* Parameter is not named, so forget it */
950 ReleaseSysCache(procTuple);
957 * build_function_result_tupdesc_t
959 * Given a pg_proc row for a function, return a tuple descriptor for the
960 * result rowtype, or NULL if the function does not have OUT parameters.
962 * Note that this does not handle resolution of polymorphic types;
963 * that is deliberate.
966 build_function_result_tupdesc_t(HeapTuple procTuple)
968 Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(procTuple);
969 Datum proallargtypes;
974 /* Return NULL if the function isn't declared to return RECORD */
975 if (procform->prorettype != RECORDOID)
978 /* If there are no OUT parameters, return NULL */
979 if (heap_attisnull(procTuple, Anum_pg_proc_proallargtypes) ||
980 heap_attisnull(procTuple, Anum_pg_proc_proargmodes))
983 /* Get the data out of the tuple */
984 proallargtypes = SysCacheGetAttr(PROCOID, procTuple,
985 Anum_pg_proc_proallargtypes,
988 proargmodes = SysCacheGetAttr(PROCOID, procTuple,
989 Anum_pg_proc_proargmodes,
992 proargnames = SysCacheGetAttr(PROCOID, procTuple,
993 Anum_pg_proc_proargnames,
996 proargnames = PointerGetDatum(NULL); /* just to be sure */
998 return build_function_result_tupdesc_d(proallargtypes,
1004 * build_function_result_tupdesc_d
1006 * Build a RECORD function's tupledesc from the pg_proc proallargtypes,
1007 * proargmodes, and proargnames arrays. This is split out for the
1008 * convenience of ProcedureCreate, which needs to be able to compute the
1009 * tupledesc before actually creating the function.
1011 * Returns NULL if there are not at least two OUT or INOUT arguments.
1014 build_function_result_tupdesc_d(Datum proallargtypes,
1023 Datum *argnames = NULL;
1030 /* Can't have output args if columns are null */
1031 if (proallargtypes == PointerGetDatum(NULL) ||
1032 proargmodes == PointerGetDatum(NULL))
1036 * We expect the arrays to be 1-D arrays of the right types; verify that.
1037 * For the OID and char arrays, we don't need to use deconstruct_array()
1038 * since the array data is just going to look like a C array of values.
1040 arr = DatumGetArrayTypeP(proallargtypes); /* ensure not toasted */
1041 numargs = ARR_DIMS(arr)[0];
1042 if (ARR_NDIM(arr) != 1 ||
1045 ARR_ELEMTYPE(arr) != OIDOID)
1046 elog(ERROR, "proallargtypes is not a 1-D Oid array");
1047 argtypes = (Oid *) ARR_DATA_PTR(arr);
1048 arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
1049 if (ARR_NDIM(arr) != 1 ||
1050 ARR_DIMS(arr)[0] != numargs ||
1052 ARR_ELEMTYPE(arr) != CHAROID)
1053 elog(ERROR, "proargmodes is not a 1-D char array");
1054 argmodes = (char *) ARR_DATA_PTR(arr);
1055 if (proargnames != PointerGetDatum(NULL))
1057 arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
1058 if (ARR_NDIM(arr) != 1 ||
1059 ARR_DIMS(arr)[0] != numargs ||
1061 ARR_ELEMTYPE(arr) != TEXTOID)
1062 elog(ERROR, "proargnames is not a 1-D text array");
1063 deconstruct_array(arr, TEXTOID, -1, false, 'i',
1064 &argnames, NULL, &nargnames);
1065 Assert(nargnames == numargs);
1068 /* zero elements probably shouldn't happen, but handle it gracefully */
1072 /* extract output-argument types and names */
1073 outargtypes = (Oid *) palloc(numargs * sizeof(Oid));
1074 outargnames = (char **) palloc(numargs * sizeof(char *));
1076 for (i = 0; i < numargs; i++)
1080 if (argmodes[i] == PROARGMODE_IN ||
1081 argmodes[i] == PROARGMODE_VARIADIC)
1083 Assert(argmodes[i] == PROARGMODE_OUT ||
1084 argmodes[i] == PROARGMODE_INOUT ||
1085 argmodes[i] == PROARGMODE_TABLE);
1086 outargtypes[numoutargs] = argtypes[i];
1088 pname = TextDatumGetCString(argnames[i]);
1091 if (pname == NULL || pname[0] == '\0')
1093 /* Parameter is not named, so gin up a column name */
1094 pname = (char *) palloc(32);
1095 snprintf(pname, 32, "column%d", numoutargs + 1);
1097 outargnames[numoutargs] = pname;
1102 * If there is no output argument, or only one, the function does not
1108 desc = CreateTemplateTupleDesc(numoutargs, false);
1109 for (i = 0; i < numoutargs; i++)
1111 TupleDescInitEntry(desc, i + 1,
1123 * RelationNameGetTupleDesc
1125 * Given a (possibly qualified) relation name, build a TupleDesc.
1127 * Note: while this works as advertised, it's seldom the best way to
1128 * build a tupdesc for a function's result type. It's kept around
1129 * only for backwards compatibility with existing user-written code.
1132 RelationNameGetTupleDesc(const char *relname)
1139 /* Open relation and copy the tuple description */
1140 relname_list = stringToQualifiedNameList(relname);
1141 relvar = makeRangeVarFromNameList(relname_list);
1142 rel = relation_openrv(relvar, AccessShareLock);
1143 tupdesc = CreateTupleDescCopy(RelationGetDescr(rel));
1144 relation_close(rel, AccessShareLock);
1152 * Given a type Oid, build a TupleDesc. (In most cases you should be
1153 * using get_call_result_type or one of its siblings instead of this
1154 * routine, so that you can handle OUT parameters, RECORD result type,
1155 * and polymorphic results.)
1157 * If the type is composite, *and* a colaliases List is provided, *and*
1158 * the List is of natts length, use the aliases instead of the relation
1159 * attnames. (NB: this usage is deprecated since it may result in
1160 * creation of unnecessary transient record types.)
1162 * If the type is a base type, a single item alias List is required.
1165 TypeGetTupleDesc(Oid typeoid, List *colaliases)
1167 TypeFuncClass functypclass = get_type_func_class(typeoid);
1168 TupleDesc tupdesc = NULL;
1171 * Build a suitable tupledesc representing the output rows
1173 if (functypclass == TYPEFUNC_COMPOSITE)
1175 /* Composite data type, e.g. a table's row type */
1176 tupdesc = lookup_rowtype_tupdesc_copy(typeoid, -1);
1178 if (colaliases != NIL)
1180 int natts = tupdesc->natts;
1183 /* does the list length match the number of attributes? */
1184 if (list_length(colaliases) != natts)
1186 (errcode(ERRCODE_DATATYPE_MISMATCH),
1187 errmsg("number of aliases does not match number of columns")));
1189 /* OK, use the aliases instead */
1190 for (varattno = 0; varattno < natts; varattno++)
1192 char *label = strVal(list_nth(colaliases, varattno));
1195 namestrcpy(&(tupdesc->attrs[varattno]->attname), label);
1198 /* The tuple type is now an anonymous record type */
1199 tupdesc->tdtypeid = RECORDOID;
1200 tupdesc->tdtypmod = -1;
1203 else if (functypclass == TYPEFUNC_SCALAR)
1205 /* Base data type, i.e. scalar */
1208 /* the alias list is required for base types */
1209 if (colaliases == NIL)
1211 (errcode(ERRCODE_DATATYPE_MISMATCH),
1212 errmsg("no column alias was provided")));
1214 /* the alias list length must be 1 */
1215 if (list_length(colaliases) != 1)
1217 (errcode(ERRCODE_DATATYPE_MISMATCH),
1218 errmsg("number of aliases does not match number of columns")));
1220 /* OK, get the column alias */
1221 attname = strVal(linitial(colaliases));
1223 tupdesc = CreateTemplateTupleDesc(1, false);
1224 TupleDescInitEntry(tupdesc,
1231 else if (functypclass == TYPEFUNC_RECORD)
1233 /* XXX can't support this because typmod wasn't passed in ... */
1235 (errcode(ERRCODE_DATATYPE_MISMATCH),
1236 errmsg("could not determine row description for function returning record")));
1240 /* crummy error message, but parser should have caught this */
1241 elog(ERROR, "function in FROM has unsupported return type");