diff -cprN head/doc/src/sgml/func.sgml work/doc/src/sgml/func.sgml
*** head/doc/src/sgml/func.sgml Tue Jan 26 11:47:08 2010
--- work/doc/src/sgml/func.sgml Thu Jan 28 09:58:12 2010
***************
*** 1789,1794 ****
--- 1789,1798 ----
+
+ See also about the aggregate
+ function string_agg.
+
Built-in Conversions
*************** SELECT NULLIF(value, '(none)') ...
*** 9837,9842 ****
--- 9841,9863 ----
+
+
+ string_agg
+
+ string_agg(expression
+ [, expression ] )
+
+
+ text
+
+
+ text
+
+ input values concatenated into an string, optionally separated by the second argument
+
+
+
sum(expression)
smallint, int,
diff -cprN head/src/backend/utils/adt/varlena.c work/src/backend/utils/adt/varlena.c
*** head/src/backend/utils/adt/varlena.c Tue Jan 26 11:47:08 2010
--- work/src/backend/utils/adt/varlena.c Thu Jan 28 11:29:55 2010
***************
*** 18,26 ****
--- 18,28 ----
#include "access/tuptoaster.h"
#include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
#include "libpq/md5.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
+ #include "nodes/execnodes.h"
#include "parser/scansup.h"
#include "regex/regex.h"
#include "utils/builtins.h"
*************** static bytea *bytea_substring(Datum str,
*** 73,78 ****
--- 75,81 ----
int L,
bool length_not_specified);
static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
+ static StringInfo makeStringAggState(fmNodePtr context);
/*****************************************************************************
*************** pg_column_size(PG_FUNCTION_ARGS)
*** 3315,3317 ****
--- 3318,3434 ----
PG_RETURN_INT32(result);
}
+
+ /*
+ * string_agg
+ *
+ * Concates values and returns string.
+ *
+ * Syntax:
+ * FUNCTION string_agg(string text, delimiter text = '')
+ * RETURNS text;
+ *
+ * Note: any NULL value is ignored.
+ */
+ static StringInfo
+ makeStringAggState(fmNodePtr context)
+ {
+ StringInfo state;
+ MemoryContext aggcontext;
+ MemoryContext oldcontext;
+
+ if (context && IsA(context, AggState))
+ aggcontext = ((AggState *) context)->aggcontext;
+ else if (context && IsA(context, WindowAggState))
+ aggcontext = ((WindowAggState *) context)->wincontext;
+ else
+ {
+ /* cannot be called directly because of internal-type argument */
+ elog(ERROR, "string_agg_transfn called in non-aggregate context");
+ aggcontext = NULL; /* keep compiler quiet */
+ }
+
+ /* Create state in aggregate context */
+ oldcontext = MemoryContextSwitchTo(aggcontext);
+ state = makeStringInfo();
+ MemoryContextSwitchTo(oldcontext);
+
+ return state;
+ }
+
+ Datum
+ string_agg1_transfn(PG_FUNCTION_ARGS)
+ {
+ StringInfo state;
+
+ state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
+
+ /* Append the element only when it isn't null */
+ if (!PG_ARGISNULL(1))
+ {
+ text *elem = PG_GETARG_TEXT_PP(1);
+
+ if (state == NULL)
+ state = makeStringAggState(fcinfo->context);
+ appendBinaryStringInfo(state, VARDATA_ANY(elem),
+ VARSIZE_ANY_EXHDR(elem));
+ }
+
+ /*
+ * The transition type for string_agg() is declared to be "internal", which
+ * is a pass-by-value type the same size as a pointer.
+ */
+ PG_RETURN_POINTER(state);
+ }
+
+ Datum
+ string_agg2_transfn(PG_FUNCTION_ARGS)
+ {
+ StringInfo state;
+
+ state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
+
+ /* Append the element only when it isn't null */
+ if (!PG_ARGISNULL(1))
+ {
+ text *elem = PG_GETARG_TEXT_PP(1);
+
+ if (state == NULL)
+ state = makeStringAggState(fcinfo->context);
+ else if (!PG_ARGISNULL(2))
+ {
+ text *delim = PG_GETARG_TEXT_PP(2);
+ appendBinaryStringInfo(state, VARDATA_ANY(delim),
+ VARSIZE_ANY_EXHDR(delim));
+ }
+
+ appendBinaryStringInfo(state, VARDATA_ANY(elem),
+ VARSIZE_ANY_EXHDR(elem));
+ }
+
+ /*
+ * The transition type for string_agg() is declared to be "internal", which
+ * is a pass-by-value type the same size as a pointer.
+ */
+ PG_RETURN_POINTER(state);
+ }
+
+ Datum
+ string_agg_finalfn(PG_FUNCTION_ARGS)
+ {
+ StringInfo state;
+
+ if (PG_ARGISNULL(0))
+ PG_RETURN_NULL();
+
+ /* cannot be called directly because of internal-type argument */
+ Assert(fcinfo->context &&
+ (IsA(fcinfo->context, AggState) ||
+ IsA(fcinfo->context, WindowAggState)));
+
+ state = (StringInfo) PG_GETARG_POINTER(0);
+ if (state != NULL)
+ PG_RETURN_TEXT_P(cstring_to_text(state->data));
+ else
+ PG_RETURN_NULL();
+ }
diff -cprN head/src/include/catalog/pg_aggregate.h work/src/include/catalog/pg_aggregate.h
*** head/src/include/catalog/pg_aggregate.h Tue Jan 5 10:25:20 2010
--- work/src/include/catalog/pg_aggregate.h Thu Jan 28 09:58:12 2010
*************** DATA(insert ( 2901 xmlconcat2 - 0
*** 223,228 ****
--- 223,232 ----
/* array */
DATA(insert ( 2335 array_agg_transfn array_agg_finalfn 0 2281 _null_ ));
+ /* text */
+ DATA(insert (3537 string_agg1_transfn string_agg_finalfn 0 2281 _null_ ));
+ DATA(insert (3538 string_agg2_transfn string_agg_finalfn 0 2281 _null_ ));
+
/*
* prototypes for functions in pg_aggregate.c
*/
diff -cprN head/src/include/catalog/pg_proc.h work/src/include/catalog/pg_proc.h
*** head/src/include/catalog/pg_proc.h Tue Jan 26 11:47:08 2010
--- work/src/include/catalog/pg_proc.h Thu Jan 28 09:58:12 2010
*************** DESCR("COVAR_SAMP(double, double) aggreg
*** 2830,2835 ****
--- 2830,2846 ----
DATA(insert OID = 2817 ( float8_corr PGNSP PGUID 12 1 0 0 f f f t f i 1 0 701 "1022" _null_ _null_ _null_ _null_ float8_corr _null_ _null_ _null_ ));
DESCR("CORR(double, double) aggregate final function");
+ DATA(insert OID = 3534 ( string_agg1_transfn PGNSP PGUID 12 1 0 0 f f f f f i 2 0 2281 "2281 25" _null_ _null_ _null_ _null_ string_agg1_transfn _null_ _null_ _null_ ));
+ DESCR("string_agg one param transition function");
+ DATA(insert OID = 3535 ( string_agg2_transfn PGNSP PGUID 12 1 0 0 f f f f f i 3 0 2281 "2281 25 25" _null_ _null_ _null_ _null_ string_agg2_transfn _null_ _null_ _null_ ));
+ DESCR("string_agg two params transition function");
+ DATA(insert OID = 3536 ( string_agg_finalfn PGNSP PGUID 12 1 0 0 f f f f f i 1 0 25 "2281" _null_ _null_ _null_ _null_ string_agg_finalfn _null_ _null_ _null_ ));
+ DESCR("string_agg final function");
+ DATA(insert OID = 3537 ( string_agg PGNSP PGUID 12 1 0 0 t f f f f i 1 0 25 "25" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+ DESCR("concatenate aggregate input into an string");
+ DATA(insert OID = 3538 ( string_agg PGNSP PGUID 12 1 0 0 t f f f f i 2 0 25 "25 25" _null_ _null_ _null_ _null_ aggregate_dummy _null_ _null_ _null_ ));
+ DESCR("concatenate aggregate input into an string with delimiter");
+
/* To ASCII conversion */
DATA(insert OID = 1845 ( to_ascii PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ to_ascii_default _null_ _null_ _null_ ));
DESCR("encode text from DB encoding to ASCII text");
diff -cprN head/src/include/utils/builtins.h work/src/include/utils/builtins.h
*** head/src/include/utils/builtins.h Tue Jan 26 11:47:08 2010
--- work/src/include/utils/builtins.h Thu Jan 28 09:58:12 2010
*************** extern Datum unknownsend(PG_FUNCTION_ARG
*** 724,729 ****
--- 724,733 ----
extern Datum pg_column_size(PG_FUNCTION_ARGS);
+ extern Datum string_agg1_transfn(PG_FUNCTION_ARGS);
+ extern Datum string_agg2_transfn(PG_FUNCTION_ARGS);
+ extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
+
/* version.c */
extern Datum pgsql_version(PG_FUNCTION_ARGS);
*************** extern Datum translate(PG_FUNCTION_ARGS)
*** 772,777 ****
--- 776,784 ----
extern Datum chr (PG_FUNCTION_ARGS);
extern Datum repeat(PG_FUNCTION_ARGS);
extern Datum ascii(PG_FUNCTION_ARGS);
+ extern Datum string_agg1_transfn(PG_FUNCTION_ARGS);
+ extern Datum string_agg2_transfn(PG_FUNCTION_ARGS);
+ extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
/* inet_net_ntop.c */
extern char *inet_net_ntop(int af, const void *src, int bits,
diff -cprN head/src/test/regress/expected/aggregates.out work/src/test/regress/expected/aggregates.out
*** head/src/test/regress/expected/aggregates.out Wed Dec 16 09:17:22 2009
--- work/src/test/regress/expected/aggregates.out Thu Jan 28 11:41:07 2010
*************** select aggfns(distinct a,a,c order by a,
*** 799,801 ****
--- 799,838 ----
ERROR: in an aggregate with DISTINCT, ORDER BY expressions must appear in argument list
LINE 1: select aggfns(distinct a,a,c order by a,b)
^
+ -- string_agg tests
+ select string_agg(a) from (values('aaaa'),('bbbb'),('cccc')) g(a);
+ string_agg
+ --------------
+ aaaabbbbcccc
+ (1 row)
+
+ select string_agg(a,',') from (values('aaaa'),('bbbb'),('cccc')) g(a);
+ string_agg
+ ----------------
+ aaaa,bbbb,cccc
+ (1 row)
+
+ select string_agg(a,',') from (values('aaaa'),(null),('bbbb'),('cccc')) g(a);
+ string_agg
+ ----------------
+ aaaa,bbbb,cccc
+ (1 row)
+
+ select string_agg(a,',') from (values(null),(null),('bbbb'),('cccc')) g(a);
+ string_agg
+ ------------
+ bbbb,cccc
+ (1 row)
+
+ select string_agg(a,',') from (values(null),(null)) g(a);
+ string_agg
+ ------------
+
+ (1 row)
+
+ select string_agg(elem, delim) from (values('A', ','), ('B', '+'), ('C', '*')) t(elem, delim);
+ string_agg
+ ------------
+ A+B*C
+ (1 row)
+
diff -cprN head/src/test/regress/sql/aggregates.sql work/src/test/regress/sql/aggregates.sql
*** head/src/test/regress/sql/aggregates.sql Wed Dec 16 09:17:22 2009
--- work/src/test/regress/sql/aggregates.sql Thu Jan 28 11:40:15 2010
*************** select aggfns(distinct a,b,c order by a,
*** 355,357 ****
--- 355,365 ----
from (values (1,1,'foo')) v(a,b,c), generate_series(1,2) i;
select aggfns(distinct a,a,c order by a,b)
from (values (1,1,'foo')) v(a,b,c), generate_series(1,2) i;
+
+ -- string_agg tests
+ select string_agg(a) from (values('aaaa'),('bbbb'),('cccc')) g(a);
+ select string_agg(a,',') from (values('aaaa'),('bbbb'),('cccc')) g(a);
+ select string_agg(a,',') from (values('aaaa'),(null),('bbbb'),('cccc')) g(a);
+ select string_agg(a,',') from (values(null),(null),('bbbb'),('cccc')) g(a);
+ select string_agg(a,',') from (values(null),(null)) g(a);
+ select string_agg(elem, delim) from (values('A', ','), ('B', '+'), ('C', '*')) t(elem, delim);