Re: PL/PGSQL: Dynamic Record Introspection

[Titus von Boxberg <ut(at)bhi-hamburg(dot)de>]

Tom Lane schrieb:
> "Titus von Boxberg" <ut(at)bhi-hamburg(dot)de> writes:
> It works for me if we want to have an "NFIELDS" construct.  Personally
> I'm still not convinced that we need one --- what's the use-case?
I have removed the NFIELDS construct
> I'd prefer arbitrary expression, but I suppose there's no harm in doing
> the simple case first and generalizing if there's demand.
I took the "no harm" way.

Attached please find the updated patch.
The patch is against HEAD of 050721.

I switched the syntax to your proposal, renamed the functions
in pl_comp.c and updated the sgml doc source and regression
test files accordingly.

Regards
Titus

*** ./doc/src/sgml/plpgsql.sgml.orig	Sat Jul  2 08:59:47 2005
--- ./doc/src/sgml/plpgsql.sgml	Sat Jul 23 17:24:54 2005
***************
*** 867,872 ****
--- 867,921 ----
     </para>
  
     <para>
+     To obtain the values of the fields the record is made up of,
+     the record variable can be qualified with the column or field
+     name. This can be done either by literally using the column name
+     or the column name for indexing the record can be taken out of a scalar
+     variable. The syntax for this notation is Record_variable.(IndexVariable).
+     To get information about the column field names of the record, 
+     a
 special expression exists that returns all column names as an array: 
+     RecordVariable.(*) .
+     Thus, the RECORD can be viewed
+     as an associative array that allows for introspection of it's contents.
+     This feature is especially useful for writing generic triggers that
+     operate on records with unknown structure.
+     Here is an example procedure that shows column names and values
+     of the predefined record NEW in a trigger procedure:
+ <programlisting>
+ 
+ CREATE OR REPLACE FUNCTION show_associative_records() RETURNS TRIGGER AS $$
+ 	DECLARE
+ 		colname		TEXT;
+ 		colcontent	TEXT;
+ 		colnames	TEXT[];
+ 		coln		INT4;
+ 		coli		INT4;
+ 	BEGIN
+ -- obtain an array with all field names of the record
+ 		colnames := NEW.(*);
+ 		RAISE NOTICE 'All column names of test record: %', colnames;
+ -- show field names and contents of record
+ 		coli := 1;
+ 		coln := array_upper(colnames,1);
+ 		RAISE NOTICE 'Number of columns in NEW: %', coln;
+ 		FOR coli IN 1 .. coln LOOP
+ 			colname := colnames[coli];
+ 			colcontent := NEW.(colname);
+ 			RAISE NOTICE 'column % of NEW: %', quote_ident(colname), quote_literal(colcontent);
+ 		END LOOP;
+ -- Do it with a fixed field name:
+ -- will have to know the column name
+ 		RAISE NOTICE 'column someint of NEW: %', quote_literal(NEW.someint);
+ 		RETURN NULL;
+ 	END;
+ $$ LANGUAGE plpgsql;
+ --CREATE TABLE test_records (someint INT8, somestring TEXT);
+ --CREATE TRIGGER tr_test_record BEFORE INSERT ON test_records FOR EACH ROW EXECUTE PROCEDURE show_associative_records();
+ 
+ </programlisting>
+    </para>
+ 
+    <para>
      Note that <literal>RECORD</> is not a true data type, only a placeholder.
      One should also realize that when a <application>PL/pgSQL</application>
      function is declared to return type <type>record</>, this is not quite the
*** ./src/pl/plpgsql/src/pl_comp.c.orig	Wed Jul  6 16:42:10 2005
--- ./src/pl/plpgsql/src/pl_comp.c	Thu Jul 21 21:28:15 2005
***************
*** 995,1001 ****
  
  				new = palloc(sizeof(PLpgSQL_recfield));
  				new->dtype = PLPGSQL_DTYPE_RECFIELD;
! 				new->fieldname = pstrdup(cp[1]);
  				new->recparentno = ns->itemno;
  
  				plpgsql_adddatum((PLpgSQL_datum *) new);
--- 995,1002 ----
  
  				new = palloc(sizeof(PLpgSQL_recfield));
  				new->dtype = PLPGSQL_DTYPE_RECFIELD;
! 				new->fieldindex.fieldname = pstrdup(cp[1]);
! 				new->fieldindex_flag = RECFIELD_USE_FIELDNAME;
  				new->recparentno = ns->itemno;
  
  				plpgsql_adddatum((PLpgSQL_datum *) new);
***************
*** 1101,1107 ****
  
  				new = palloc(sizeof(PLpgSQL_recfield));
  				new->dtype = PLPGSQL_DTYPE_RECFIELD;
! 				new->fieldname = pstrdup(cp[2]);
  				new->recparentno = ns->itemno;
  
  				plpgsql_adddatum((PLpgSQL_datum *) new);
--- 1102,1109 ----
  
  				new = palloc(sizeof(PLpgSQL_recfield));
  				new->dtype = PLPGSQL_DTYPE_RECFIELD;
! 				new->fieldindex.fieldname = pstrdup(cp[2]);
! 				new->fieldindex_flag = RECFIELD_USE_FIELDNAME;
  				new->recparentno = ns->itemno;
  
  				plpgsql_adddatum((PLpgSQL_datum *) new);
***************
*** 1550,1555 ****
--- 1552,1683 ----
  	MemoryContextSwitchTo(oldCxt);
  	return T_DTYPE;
  }
+ 
+ /* ----------
+  * plpgsql_parse_recindex
+  * lookup associative index into record
+  * ----------
+  */
+ int
+ plpgsql_parse_recindex(char *word)
+ {
+ 	PLpgSQL_nsitem *ns1, *ns2;
+ 	char		*cp[2];
+ 	int		ret = T_ERROR;
+ 	char		*fieldvar;
+ 	int		fl;
+ 
+ 	/* Do case conversion and word separation */
+ 	plpgsql_convert_ident(word, cp, 2);
+ 	Assert(cp[1] != NULL);
+ 
+ 	/* cleanup the "(identifier)" string to "identifier" */
+ 	fieldvar = cp[1];
+ 	Assert(*fieldvar == '(');
+ 	++fieldvar;	/* get rid of ( */
+ 
+ 	fl = strlen(fieldvar);
+ 	Assert(fieldvar[fl-1] == ')');
+ 	fieldvar[fl-1] = 0; /* get rid of ) */
+ 
+ 	/*
+ 	 * Lookup the first word
+ 	 */
+ 	ns1 = plpgsql_ns_lookup(cp[0], NULL);
+ 	if ( ns1 == NULL )
+ 	{
+ 		pfree(cp[0]);
+ 		pfree(cp[1]);
+ 		return T_ERROR;
+ 	}
+ 
+ 	ns2 = plpgsql_ns_lookup(fieldvar, NULL);
+ 	pfree(cp[0]);
+ 	pfree(cp[1]);
+ 	if ( ns2 == NULL )	/* name lookup failed */
+ 		return T_ERROR;
+ 
+ 	switch (ns1->itemtype)
+ 	{
+ 		case PLPGSQL_NSTYPE_REC:
+ 			{
+ 				/*
+ 				 * First word is a record name, so second word must be an
+ 				 * variable holding the field name in this record.
+ 				 */
+ 				if ( ns2->itemtype == PLPGSQL_NSTYPE_VAR ) {
+ 					PLpgSQL_recfield *new;
+ 
+ 					new = palloc(sizeof(PLpgSQL_recfield));
+ 					new->dtype = PLPGSQL_DTYPE_RECFIELD;
+ 					new->fieldindex.indexvar_no = ns2->itemno;
+ 					new->fieldindex_flag = RECFIELD_USE_INDEX_VAR;
+ 					new->recparentno = ns1->itemno;
+ 
+ 					plpgsql_adddatum((PLpgSQL_datum *) new);
+ 
+ 					plpgsql_yylval.scalar = (PLpgSQL_datum *) new;
+ 					ret =  T_SCALAR;
+ 				} 
+ 				break;
+ 			}
+ 		default:
+ 			break;
+ 	}
+ 	return ret;
+ } 
+ 
+ 
+ /* ----------
+  * plpgsql_parse_recfieldnames
+  * create fieldnames of a record
+  * ----------
+  */
+ int
+ plpgsql_parse_recfieldnames(char *word)
+ {
+ 	PLpgSQL_nsitem	*ns1;
+ 	char		*cp[2];
+ 	int		ret = T_ERROR;
+ 
+ 	/* Do case conversion and word separation */
+ 	plpgsql_convert_ident(word, cp, 2);
+ 
+ 	/*
+ 	 * Lookup the first word
+ 	 */
+ 	ns1 = plpgsql_ns_lookup(cp[0], NULL);
+ 	if ( ns1 == NULL )
+ 	{
+ 		pfree(cp[0]);
+ 		pfree(cp[1]);
+ 		return T_ERROR;
+ 	}
+ 
+ 	pfree(cp[0]);
+ 	pfree(cp[1]);
+ 
+ 	switch (ns1->itemtype)
+ 	{
+ 		case PLPGSQL_NSTYPE_REC:
+ 			{
+ 				PLpgSQL_recfieldproperties *new;
+ 
+ 				new = palloc(sizeof(PLpgSQL_recfieldproperties));
+ 				new->dtype = PLPGSQL_DTYPE_RECFIELDNAMES;
+ 				new->recparentno = ns1->itemno;
+ 				new->save_fieldnames = NULL;
+ 				plpgsql_adddatum((PLpgSQL_datum *) new);
+ 				plpgsql_yylval.scalar = (PLpgSQL_datum *) new;
+ 				ret =  T_SCALAR;	/* ??? */
+ 				break;
+ 			}
+ 		default:
+ 			break;
+ 	}
+ 	return ret;
+ }
+ 
  
  /*
   * plpgsql_build_variable - build a datum-array entry of a given
*** ./src/pl/plpgsql/src/pl_exec.c.orig	Sun Jun 26 22:05:42 2005
--- ./src/pl/plpgsql/src/pl_exec.c	Sat Jul 23 17:13:32 2005
***************
*** 716,721 ****
--- 716,722 ----
  		case PLPGSQL_DTYPE_RECFIELD:
  		case PLPGSQL_DTYPE_ARRAYELEM:
  		case PLPGSQL_DTYPE_TRIGARG:
+ 		case PLPGSQL_DTYPE_RECFIELDNAMES:
  			/*
  			 * These datum records are read-only at runtime, so no need
  			 * to copy them
***************
*** 825,830 ****
--- 826,832 ----
  
  			case PLPGSQL_DTYPE_RECFIELD:
  			case PLPGSQL_DTYPE_ARRAYELEM:
+ 			case PLPGSQL_DTYPE_RECFIELDNAMES:
  				break;
  
  			default:
***************
*** 2146,2151 ****
--- 2148,2155 ----
  static void
  exec_eval_cleanup(PLpgSQL_execstate *estate)
  {
+ 	int		i;
+ 	ArrayType	*a;
  	/* Clear result of a full SPI_execute */
  	if (estate->eval_tuptable != NULL)
  		SPI_freetuptable(estate->eval_tuptable);
***************
*** 2154,2159 ****
--- 2158,2171 ----
  	/* Clear result of exec_eval_simple_expr (but keep the econtext) */
  	if (estate->eval_econtext != NULL)
  		ResetExprContext(estate->eval_econtext);
+ 	for ( i = 0; i < estate->ndatums; ++i ) {
+ 		if ( estate->datums[i]->dtype == PLPGSQL_DTYPE_RECFIELDNAMES ) {
+ 			a = ((PLpgSQL_recfieldproperties *)(estate->datums[i]))->save_fieldnames;
+ 			if ( a )
+ 				pfree(a);
+ 			((PLpgSQL_recfieldproperties *)(estate->datums[i]))->save_fieldnames = NULL;
+ 		}
+ 	}
  }
  
  
***************
*** 3154,3165 ****
  				 * Get the number of the records field to change and the
  				 * number of attributes in the tuple.
  				 */
! 				fno = SPI_fnumber(rec->tupdesc, recfield->fieldname);
! 				if (fno == SPI_ERROR_NOATTRIBUTE)
! 					ereport(ERROR,
! 							(errcode(ERRCODE_UNDEFINED_COLUMN),
! 							 errmsg("record \"%s\" has no field \"%s\"",
! 									rec->refname, recfield->fieldname)));
  				fno--;
  				natts = rec->tupdesc->natts;
  
--- 3166,3200 ----
  				 * Get the number of the records field to change and the
  				 * number of attributes in the tuple.
  				 */
! 				if ( recfield->fieldindex_flag == RECFIELD_USE_FIELDNAME ) {
! 					fno = SPI_fnumber(rec->tupdesc, recfield->fieldindex.fieldname);
! 					if (fno == SPI_ERROR_NOATTRIBUTE)
! 						ereport(ERROR,
! 								(errcode(ERRCODE_UNDEFINED_COLUMN),
! 								 errmsg("record \"%s\" has no field \"%s\"",
! 										rec->refname, recfield->fieldindex.fieldname)));
! 				}
! 				else if ( recfield->fieldindex_flag == RECFIELD_USE_INDEX_VAR ) {
! 					PLpgSQL_var * idxvar = (PLpgSQL_var *) (estate->datums[recfield->fieldindex.indexvar_no]);
! 					char * fname = convert_value_to_string(idxvar->value, idxvar->datatype->typoid);
! 					if ( fname == NULL )
! 						ereport(ERROR,
! 								(errcode(ERRCODE_UNDEFINED_COLUMN),
! 								errmsg("record \"%s\": cannot evaluate variable to record index string",
! 										rec->refname)));
! 					fno = SPI_fnumber(rec->tupdesc, fname);
! 					pfree(fname);
! 					if (fno == SPI_ERROR_NOATTRIBUTE)
! 						ereport(ERROR,
! 								(errcode(ERRCODE_UNDEFINED_COLUMN),
! 								 errmsg("record \"%s\" has no field \"%s\"",
! 										rec->refname, fname)));
! 				}
! 				else
! 					ereport(ERROR,
! 						(errcode(ERRCODE_UNDEFINED_COLUMN),
! 						errmsg("record \"%s\": internal error",
! 									rec->refname)));
  				fno--;
  				natts = rec->tupdesc->natts;
  
***************
*** 3497,3518 ****
  					   errmsg("record \"%s\" is not assigned yet",
  							  rec->refname),
  					   errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
! 				fno = SPI_fnumber(rec->tupdesc, recfield->fieldname);
! 				if (fno == SPI_ERROR_NOATTRIBUTE)
! 					ereport(ERROR,
! 							(errcode(ERRCODE_UNDEFINED_COLUMN),
! 							 errmsg("record \"%s\" has no field \"%s\"",
! 									rec->refname, recfield->fieldname)));
! 				*typeid = SPI_gettypeid(rec->tupdesc, fno);
! 				*value = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull);
! 				if (expectedtypeid != InvalidOid && expectedtypeid != *typeid)
! 					ereport(ERROR,
! 							(errcode(ERRCODE_DATATYPE_MISMATCH),
! 							 errmsg("type of \"%s.%s\" does not match that when preparing the plan",
! 									rec->refname, recfield->fieldname)));
! 				break;
! 			}
! 
  		case PLPGSQL_DTYPE_TRIGARG:
  			{
  				PLpgSQL_trigarg *trigarg = (PLpgSQL_trigarg *) datum;
--- 3532,3656 ----
  					   errmsg("record \"%s\" is not assigned yet",
  							  rec->refname),
  					   errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
! 				if ( recfield->fieldindex_flag == RECFIELD_USE_FIELDNAME ) {
! 					fno = SPI_fnumber(rec->tupdesc, recfield->fieldindex.fieldname);
! 					if (fno == SPI_ERROR_NOATTRIBUTE)
! 						ereport(ERROR,
! 								(errcode(ERRCODE_UNDEFINED_COLUMN),
! 								 errmsg("record \"%s\" has no field \"%s\"",
! 										rec->refname, recfield->fieldindex.fieldname)));
! 				}
! 				else if ( recfield->fieldindex_flag == RECFIELD_USE_INDEX_VAR ) {
! 					PLpgSQL_var * idxvar = (PLpgSQL_var *) (estate->datums[recfield->fieldindex.indexvar_no]);
! 					char * fname = convert_value_to_string(idxvar->value, idxvar->datatype->typoid);
! 					if ( fname == NULL )
! 						ereport(ERROR,
! 								(errcode(ERRCODE_UNDEFINED_COLUMN),
! 								errmsg("record \"%s\": cannot evaluate variable to record index string",
! 										rec->refname)));
! 					fno = SPI_fnumber(rec->tupdesc, fname);
! 					pfree(fname);
! 					if (fno == SPI_ERROR_NOATTRIBUTE)
! 						ereport(ERROR,
! 								(errcode(ERRCODE_UNDEFINED_COLUMN),
! 								 errmsg("record \"%s\" has no field \"%s\"",
! 										rec->refname, fname)));
! 				}
! 				else
! 					ereport(ERROR,
! 						(errcode(ERRCODE_UNDEFINED_COLUMN),
! 						errmsg("record \"%s\": internal error",
! 								rec->refname)));
! 
! 				/* Do not allow typeids to become "narrowed" by InvalidOids 
! 				causing specialized typeids from the tuple restricting the destination */
! 				if ( expectedtypeid != InvalidOid && expectedtypeid != SPI_gettypeid(rec->tupdesc, fno) ) {
! 					Datum cval = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull);
! 					cval =   exec_simple_cast_value(cval,
! 									SPI_gettypeid(rec->tupdesc, fno),
! 									expectedtypeid,
! 									-1,
! 									isnull);
! 
! 					*value = cval;
! 					*typeid = expectedtypeid;
! 					/* ereport(ERROR,
! 							(errcode(ERRCODE_DATATYPE_MISMATCH),
! 							 errmsg("type of \"%s\" does not match that when preparing the plan",
! 									rec->refname)));
! 					*/
! 				} 
! 				else { /* expected typeid matches */
! 					*value = SPI_getbinval(rec->tup, rec->tupdesc, fno, isnull);
! 					*typeid = SPI_gettypeid(rec->tupdesc, fno);
! 				} 
! 				break;
! 			}
! 
! 		case PLPGSQL_DTYPE_RECFIELDNAMES:
! 			/* Construct array datum from record field names */
! 			{
! 				Oid			arraytypeid,
! 							arrayelemtypeid = TEXTOID;
! 				int16			arraytyplen,
! 							elemtyplen;
! 				bool			elemtypbyval;
! 				char			elemtypalign;
! 				ArrayType		*arrayval;
! 				PLpgSQL_recfieldproperties * recfp = (PLpgSQL_recfieldproperties *) datum;
! 				PLpgSQL_rec		*rec = (PLpgSQL_rec *) (estate->datums[recfp->recparentno]);
! 				int			fc, tfc = 0;
! 				Datum			*arrayelems;
! 				char			*fieldname;
! 
! 				if (!HeapTupleIsValid(rec->tup))
! 					ereport(ERROR,
! 					  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
! 					   errmsg("record \"%s\" is not assigned yet",
! 							  rec->refname),
! 					   errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
! 				arrayelems = palloc(sizeof(Datum) * rec->tupdesc->natts);
! 				arraytypeid = get_array_type(arrayelemtypeid);
! 				arraytyplen = get_typlen(arraytypeid);
! 				get_typlenbyvalalign(arrayelemtypeid,
! 						     &elemtyplen,
! 						     &elemtypbyval,
! 						     &elemtypalign);
! 
! 				if ( expectedtypeid != InvalidOid && expectedtypeid != arraytypeid )
! 					ereport(ERROR,
! 							(errcode(ERRCODE_DATATYPE_MISMATCH),
! 							 errmsg("type of \"%s\" does not match array type when preparing the plan",
! 									rec->refname)));
! 				for ( fc = 0; fc < rec->tupdesc->natts; ++fc ) {
! 					fieldname = SPI_fname(rec->tupdesc, fc+1);
! 					if ( fieldname ) {
! 						arrayelems[fc] = DirectFunctionCall1(textin, CStringGetDatum(fieldname));
! 						pfree(fieldname);
! 						++tfc;
! 					} 
! 				} 
! 				arrayval = construct_array(arrayelems, tfc,
! 							 arrayelemtypeid,
! 							 elemtyplen,
! 							 elemtypbyval,
! 							 elemtypalign);
! 
! 
! 				/* construct_array copies data; free temp elem array */
! 				for ( fc = 0; fc < tfc; ++fc )
! 					pfree(DatumGetPointer(arrayelems[fc]));
! 				pfree(arrayelems);
! 				*value = PointerGetDatum(arrayval);
! 				*typeid = arraytypeid;
! 				*isnull = false;
! 				/* need to save the pointer because otherwise it does not get freed */
! 				if ( recfp->save_fieldnames )
! 					pfree(recfp->save_fieldnames);
! 				recfp->save_fieldnames = arrayval;
! 				break;
! 			}
! 
  		case PLPGSQL_DTYPE_TRIGARG:
  			{
  				PLpgSQL_trigarg *trigarg = (PLpgSQL_trigarg *) datum;
***************
*** 3610,3616 ****
--- 3748,3790 ----
  	 */
  	if (expr->plan == NULL)
  		exec_prepare_plan(estate, expr);
+ 	else {
+ 		/*
+ 		 * check for any subexpressions with varying type in the expression 
+ 		 * currently (July 05), this is a record field of a record indexed by a variable
+ 		 */
+ 		int			i;
+ 		PLpgSQL_datum		*d;
+ 		PLpgSQL_recfield	*rf;
+ 		for ( i = 0; i < expr->nparams; ++i ) {
+ 			d = estate->datums[expr->params[i]];
+ 			if ( d->dtype == PLPGSQL_DTYPE_RECFIELD ) {
+ 				rf = (PLpgSQL_recfield *)d;
+ 				if ( rf->fieldindex_flag == RECFIELD_USE_INDEX_VAR )
+ 					break;
+ 			}
+ 		}
+ 		if ( i < expr->nparams ) { /* expr may change it's type */
+ 			/* Make sure expr is not in the list of active simple expressions
+ 			   because exec_prepare_plan()/exec_simple_check_plan()... 
+ 			   will destroy the link to the next simple expression */
+ 			PLpgSQL_expr *e, *enext;
+ 			PLpgSQL_expr **eprevnext = &active_simple_exprs;
+ 			for (e = active_simple_exprs; e; e = enext)
+ 			{
+ 				enext = e->expr_simple_next;
+ 				if ( e == expr ) /* found us in the list */
+ 					*eprevnext = enext; /* discard us */
+ 				else
+ 					eprevnext = &(e->expr_simple_next);
+ 			}
  
+ 			/* now discard the plan and get new one */
+ 			SPI_freeplan(expr->plan);
+ 			expr->plan = NULL;
+ 			exec_prepare_plan(estate, expr);
+ 		}
+ 	}
  	/*
  	 * If this is a simple expression, bypass SPI and use the executor
  	 * directly
*** ./src/pl/plpgsql/src/pl_funcs.c.orig	Wed Jun 22 01:35:02 2005
--- ./src/pl/plpgsql/src/pl_funcs.c	Thu Jul 21 21:03:40 2005
***************
*** 1066,1074 ****
  				printf("REC %s\n", ((PLpgSQL_rec *) d)->refname);
  				break;
  			case PLPGSQL_DTYPE_RECFIELD:
! 				printf("RECFIELD %-16s of REC %d\n",
! 					   ((PLpgSQL_recfield *) d)->fieldname,
! 					   ((PLpgSQL_recfield *) d)->recparentno);
  				break;
  			case PLPGSQL_DTYPE_ARRAYELEM:
  				printf("ARRAYELEM of VAR %d subscript ",
--- 1066,1078 ----
  				printf("REC %s\n", ((PLpgSQL_rec *) d)->refname);
  				break;
  			case PLPGSQL_DTYPE_RECFIELD:
! 				if ( ((PLpgSQL_recfield *) d)->fieldindex_flag == RECFIELD_USE_FIELDNAME )
! 					printf("RECFIELD %-16s of REC %d\n",
! 						   ((PLpgSQL_recfield *) d)->fieldindex.fieldname,
! 						   ((PLpgSQL_recfield *) d)->recparentno);
! 				else
! 					printf("RECFIELD Variable of REC %d\n",
! 						   ((PLpgSQL_recfield *) d)->recparentno);
  				break;
  			case PLPGSQL_DTYPE_ARRAYELEM:
  				printf("ARRAYELEM of VAR %d subscript ",
*** ./src/pl/plpgsql/src/plpgsql.h.orig	Thu Jul 21 21:00:57 2005
--- ./src/pl/plpgsql/src/plpgsql.h	Thu Jul 21 21:15:42 2005
***************
*** 73,79 ****
  	PLPGSQL_DTYPE_RECFIELD,
  	PLPGSQL_DTYPE_ARRAYELEM,
  	PLPGSQL_DTYPE_EXPR,
! 	PLPGSQL_DTYPE_TRIGARG
  };
  
  /* ----------
--- 73,80 ----
  	PLPGSQL_DTYPE_RECFIELD,
  	PLPGSQL_DTYPE_ARRAYELEM,
  	PLPGSQL_DTYPE_EXPR,
! 	PLPGSQL_DTYPE_TRIGARG,
! 	PLPGSQL_DTYPE_RECFIELDNAMES
  };
  
  /* ----------
***************
*** 269,278 ****
  {								/* Field in record */
  	int			dtype;
  	int			rfno;
! 	char	   *fieldname;
  	int			recparentno;	/* dno of parent record */
  } PLpgSQL_recfield;
  
  
  typedef struct
  {								/* Element of array variable */
--- 270,294 ----
  {								/* Field in record */
  	int			dtype;
  	int			rfno;
! 	union {
! 		char	*fieldname;
! 		int	indexvar_no;		/* dno of variable holding index string */
! 	} fieldindex;
! 	enum {
! 		RECFIELD_USE_FIELDNAME,
! 		RECFIELD_USE_INDEX_VAR,
! 	}	fieldindex_flag;
  	int			recparentno;	/* dno of parent record */
  } PLpgSQL_recfield;
  
+ typedef struct
+ {								/* Field in record */
+ 	int			dtype;
+ 	int			rfno;
+ 	int			recparentno;			/* dno of parent record */
+ 	ArrayType *		save_fieldnames;
+ } PLpgSQL_recfieldproperties;
+ 
  
  typedef struct
  {								/* Element of array variable */
***************
*** 678,683 ****
--- 694,701 ----
  extern int	plpgsql_parse_tripwordtype(char *word);
  extern int	plpgsql_parse_wordrowtype(char *word);
  extern int	plpgsql_parse_dblwordrowtype(char *word);
+ extern int	plpgsql_parse_recfieldnames(char *word);
+ extern int	plpgsql_parse_recindex(char *word);
  extern PLpgSQL_type *plpgsql_parse_datatype(const char *string);
  extern PLpgSQL_type *plpgsql_build_datatype(Oid typeOid, int32 typmod);
  extern PLpgSQL_variable *plpgsql_build_variable(const char *refname, int lineno,
*** ./src/pl/plpgsql/src/scan.l.orig	Sun Jun 26 19:16:07 2005
--- ./src/pl/plpgsql/src/scan.l	Thu Jul 21 21:28:20 2005
***************
*** 243,248 ****
--- 243,254 ----
  {param}{space}*\.{space}*{identifier}{space}*%ROWTYPE	{
  	plpgsql_error_lineno = plpgsql_scanner_lineno();
  	return plpgsql_parse_dblwordrowtype(yytext); }
+ {identifier}{space}*\.\(\*\)		{
+ 	plpgsql_error_lineno = plpgsql_scanner_lineno();
+ 	return plpgsql_parse_recfieldnames(yytext); }
+ {identifier}{space}*\.\({identifier}\)		{
+ 	plpgsql_error_lineno = plpgsql_scanner_lineno();
+ 	return plpgsql_parse_recindex(yytext); }
  
  {digit}+		{ return T_NUMBER;			}
  
*** ./src/test/regress/expected/plpgsql.out.orig	Sat Jul  2 08:59:48 2005
--- ./src/test/regress/expected/plpgsql.out	Thu Jul 21 22:32:52 2005
***************
*** 2721,2723 ****
--- 2721,2761 ----
  $$ language plpgsql;
  ERROR:  end label "outer_label" specified for unlabelled block
  CONTEXT:  compile of PL/pgSQL function "end_label4" near line 5
+ -- check introspective records
+ create table ritest (i INT4, t TEXT);
+ insert into ritest (i, t) VALUES (1, 'sometext');
+ create function test_record() returns void as $$
+ declare
+   cname text;
+   tval  text;
+   ival  int4;
+   tval2 text;
+   ival2 int4;
+   columns text[];
+   r     RECORD;
+ begin
+   SELECT INTO r * FROM ritest WHERE i = 1;
+   ival := r.i;
+   tval := r.t;
+   RAISE NOTICE 'ival=%, tval=%', ival, tval;
+   cname := 'i';
+   ival2 := r.(cname);
+   cname :='t';
+   tval2 := r.(cname);
+   RAISE NOTICE 'ival2=%, tval2=%', ival2, tval2;
+   columns := r.(*);
+   RAISE NOTICE 'fieldnames=%', columns;
+   RETURN;
+ end;
+ $$ language plpgsql;
+ select test_record();
+ NOTICE:  ival=1, tval=sometext
+ NOTICE:  ival2=1, tval2=sometext
+ NOTICE:  fieldnames={i,t}
+  test_record 
+ -------------
+  
+  (1 row)
+ 
+ drop table ritest;
+ drop function test_record();
*** ./src/test/regress/sql/plpgsql.sql.orig	Thu Jul 21 21:04:43 2005
--- ./src/test/regress/sql/plpgsql.sql	Thu Jul 21 21:36:11 2005
***************
*** 2280,2282 ****
--- 2280,2314 ----
    end loop outer_label;
  end;
  $$ language plpgsql;
+ 
+ -- check introspective records
+ create table ritest (i INT4, t TEXT);
+ insert into ritest (i, t) VALUES (1, 'sometext');
+ create function test_record() returns void as $$
+ declare
+   cname text;
+   tval  text;
+   ival  int4;
+   tval2 text;
+   ival2 int4;
+   columns text[];
+   r     RECORD;
+ begin
+   SELECT INTO r * FROM ritest WHERE i = 1;
+   ival := r.i;
+   tval := r.t;
+   RAISE NOTICE 'ival=%, tval=%', ival, tval;
+   cname := 'i';
+   ival2 := r.(cname);
+   cname :='t';
+   tval2 := r.(cname);
+   RAISE NOTICE 'ival2=%, tval2=%', ival2, tval2;
+   columns := r.(*);
+   RAISE NOTICE 'fieldnames=%', columns;
+   RETURN;
+ end;
+ $$ language plpgsql;
+ select test_record();
+ drop table ritest;
+ drop function test_record();
+