Skip to content

Commit f98f6ee

Browse files
peterepetere
committed
array_length() function, and for SQL compatibility also cardinality()
function as a special case. This version still has the suspicious behavior of returning null for an empty array (rather than zero), but this may need a wholesale revision of empty array behavior, currently under discussion. Jim Nasby, Robert Haas, Peter Eisentraut
1 parent 4c22564 commit f98f6ee

File tree

8 files changed

+135
-7
lines changed

8 files changed

+135
-7
lines changed

‎doc/src/sgml/array.sgml

Lines changed: 13 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.67 2008/10/29 11:24:52 petere Exp $ -->
1+
<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.68 2008/11/12 13:09:27 petere Exp $ -->
22

33
<sect1 id="arrays">
44
<title>Arrays</title>
@@ -324,6 +324,18 @@ SELECT array_upper(schedule, 1) FROM sal_emp WHERE name = 'Carol';
324324
-------------
325325
2
326326
(1 row)
327+
</programlisting>
328+
329+
<function>array_length</function> will return the length of a specified
330+
array dimension:
331+
332+
<programlisting>
333+
SELECT array_length(schedule, 1) FROM sal_emp WHERE name = 'Carol';
334+
335+
array_length
336+
--------------
337+
2
338+
(1 row)
327339
</programlisting>
328340
</para>
329341
</sect2>

‎doc/src/sgml/func.sgml

Lines changed: 25 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.456 2008/11/07 22:54:41 tgl Exp $ -->
1+
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.457 2008/11/12 13:09:27 petere Exp $ -->
22

33
<chapter id="functions">
44
<title>Functions and Operators</title>
@@ -9408,6 +9408,17 @@ SELECT NULLIF(value, '(none)') ...
94089408
<entry><literal>array_fill(7, ARRAY[3], ARRAY[2])</literal></entry>
94099409
<entry><literal>[2:4]={7,7,7}</literal></entry>
94109410
</row>
9411+
<row>
9412+
<entry>
9413+
<literal>
9414+
<function>array_length</function>(<type>anyarray</type>, <type>int</type>)
9415+
</literal>
9416+
</entry>
9417+
<entry><type>int</type></entry>
9418+
<entry>returns the length of the requested array dimension</entry>
9419+
<entry><literal>array_length(array[1,2,3], 1)</literal></entry>
9420+
<entry><literal>3</literal></entry>
9421+
</row>
94119422
<row>
94129423
<entry>
94139424
<literal>
@@ -9452,6 +9463,19 @@ SELECT NULLIF(value, '(none)') ...
94529463
<entry><literal>array_upper(ARRAY[1,2,3,4], 1)</literal></entry>
94539464
<entry><literal>4</literal></entry>
94549465
</row>
9466+
<row>
9467+
<entry>
9468+
<literal>
9469+
<function>cardinality</function>(<type>anyarray</type>)
9470+
</literal>
9471+
</entry>
9472+
<entry><type>int</type></entry>
9473+
<entry>returns the length of the first dimension of the array
9474+
(special case of <function>array_length</function> for SQL
9475+
compatibility)</entry>
9476+
<entry><literal>cardinality(array[1,2,3])</literal></entry>
9477+
<entry><literal>3</literal></entry>
9478+
</row>
94559479
<row>
94569480
<entry>
94579481
<literal>

‎src/backend/utils/adt/arrayfuncs.c

Lines changed: 29 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.148 2008/11/04 14:49:11 petere Exp $
11+
* $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.149 2008/11/12 13:09:27 petere Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -1640,6 +1640,34 @@ array_upper(PG_FUNCTION_ARGS)
16401640
PG_RETURN_INT32(result);
16411641
}
16421642

1643+
/*
1644+
* array_length :
1645+
* returns the length, of the dimension requested, for
1646+
* the array pointed to by "v", as an int4
1647+
*/
1648+
Datum
1649+
array_length(PG_FUNCTION_ARGS)
1650+
{
1651+
ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
1652+
int reqdim = PG_GETARG_INT32(1);
1653+
int *dimv;
1654+
int result;
1655+
1656+
/* Sanity check: does it look like an array at all? */
1657+
if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
1658+
PG_RETURN_NULL();
1659+
1660+
/* Sanity check: was the requested dim valid */
1661+
if (reqdim <= 0 || reqdim > ARR_NDIM(v))
1662+
PG_RETURN_NULL();
1663+
1664+
dimv = ARR_DIMS(v);
1665+
1666+
result = dimv[reqdim - 1];
1667+
1668+
PG_RETURN_INT32(result);
1669+
}
1670+
16431671
/*
16441672
* array_ref :
16451673
* This routine takes an array pointer and a subscript array and returns

‎src/include/catalog/catversion.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -37,7 +37,7 @@
3737
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
3838
* Portions Copyright (c) 1994, Regents of the University of California
3939
*
40-
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.503 2008/11/09 21:24:33 tgl Exp $
40+
* $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.504 2008/11/12 13:09:27 petere Exp $
4141
*
4242
*-------------------------------------------------------------------------
4343
*/
@@ -53,6 +53,6 @@
5353
*/
5454

5555
/* yyyymmddN */
56-
#define CATALOG_VERSION_NO 200811091
56+
#define CATALOG_VERSION_NO 200811121
5757

5858
#endif

‎src/include/catalog/pg_proc.h

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.524 2008/11/04 14:49:11 petere Exp $
10+
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.525 2008/11/12 13:09:28 petere Exp $
1111
*
1212
* NOTES
1313
* The script catalog/genbki.sh reads this file and generates .bki
@@ -996,6 +996,10 @@ DATA(insert OID = 2091 ( array_lower PGNSP PGUID 12 1 0 0 f f t f i 2 23 "22
996996
DESCR("array lower dimension");
997997
DATA(insert OID = 2092 ( array_upper PGNSP PGUID 12 1 0 0 f f t f i 2 23 "2277 23" _null_ _null_ _null_ array_upper _null_ _null_ _null_ ));
998998
DESCR("array upper dimension");
999+
DATA(insert OID = 2176 ( array_length PGNSP PGUID 12 1 0 0 f f t f i 2 23 "2277 23" _null_ _null_ _null_ array_length _null_ _null_ _null_ ));
1000+
DESCR("array length");
1001+
DATA(insert OID = 2179 ( cardinality PGNSP PGUID 14 1 0 0 f f t f i 1 23 "2277" _null_ _null_ _null_ "select array_length($1, 1)" _null_ _null_ _null_ ));
1002+
DESCR("array length");
9991003
DATA(insert OID = 378 ( array_append PGNSP PGUID 12 1 0 0 f f f f i 2 2277 "2277 2283" _null_ _null_ _null_ array_push _null_ _null_ _null_ ));
10001004
DESCR("append element onto end of array");
10011005
DATA(insert OID = 379 ( array_prepend PGNSP PGUID 12 1 0 0 f f f f i 2 2277 "2283 2277" _null_ _null_ _null_ array_push _null_ _null_ _null_ ));

‎src/include/utils/array.h

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -49,7 +49,7 @@
4949
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
5050
* Portions Copyright (c) 1994, Regents of the University of California
5151
*
52-
* $PostgreSQL: pgsql/src/include/utils/array.h,v 1.69 2008/11/04 14:49:12 petere Exp $
52+
* $PostgreSQL: pgsql/src/include/utils/array.h,v 1.70 2008/11/12 13:09:28 petere Exp $
5353
*
5454
*-------------------------------------------------------------------------
5555
*/
@@ -199,6 +199,7 @@ extern Datum array_ndims(PG_FUNCTION_ARGS);
199199
extern Datum array_dims(PG_FUNCTION_ARGS);
200200
extern Datum array_lower(PG_FUNCTION_ARGS);
201201
extern Datum array_upper(PG_FUNCTION_ARGS);
202+
extern Datum array_length(PG_FUNCTION_ARGS);
202203
extern Datum array_larger(PG_FUNCTION_ARGS);
203204
extern Datum array_smaller(PG_FUNCTION_ARGS);
204205
extern Datum generate_subscripts(PG_FUNCTION_ARGS);

‎src/test/regress/expected/arrays.out

Lines changed: 50 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1075,3 +1075,53 @@ select array_to_string(string_to_array('1|2|3', '|'), '|');
10751075
1|2|3
10761076
(1 row)
10771077

1078+
select array_length(array[1,2,3], 1);
1079+
array_length
1080+
--------------
1081+
3
1082+
(1 row)
1083+
1084+
select array_length(array[[1,2,3], [4,5,6]], 0);
1085+
array_length
1086+
--------------
1087+
1088+
(1 row)
1089+
1090+
select array_length(array[[1,2,3], [4,5,6]], 1);
1091+
array_length
1092+
--------------
1093+
2
1094+
(1 row)
1095+
1096+
select array_length(array[[1,2,3], [4,5,6]], 2);
1097+
array_length
1098+
--------------
1099+
3
1100+
(1 row)
1101+
1102+
select array_length(array[[1,2,3], [4,5,6]], 3);
1103+
array_length
1104+
--------------
1105+
1106+
(1 row)
1107+
1108+
select cardinality(array[1,2,3]);
1109+
cardinality
1110+
-------------
1111+
3
1112+
(1 row)
1113+
1114+
select cardinality(array[[1,2,3], [4,5,6]]);
1115+
cardinality
1116+
-------------
1117+
2
1118+
(1 row)
1119+
1120+
select c, cardinality(c), d, cardinality(d) from arrtest;
1121+
c | cardinality | d | cardinality
1122+
-------------------+-------------+---------------+-------------
1123+
{} | | {} |
1124+
{foobar,new_word} | 2 | {{elt1,elt2}} | 1
1125+
{foo,new_word} | 2 | {bar,foo} | 2
1126+
(3 rows)
1127+

‎src/test/regress/sql/arrays.sql

Lines changed: 9 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -386,3 +386,12 @@ select string_to_array('1|2|3', NULL);
386386
select string_to_array(NULL, '|');
387387

388388
select array_to_string(string_to_array('1|2|3', '|'), '|');
389+
390+
select array_length(array[1,2,3], 1);
391+
select array_length(array[[1,2,3], [4,5,6]], 0);
392+
select array_length(array[[1,2,3], [4,5,6]], 1);
393+
select array_length(array[[1,2,3], [4,5,6]], 2);
394+
select array_length(array[[1,2,3], [4,5,6]], 3);
395+
select cardinality(array[1,2,3]);
396+
select cardinality(array[[1,2,3], [4,5,6]]);
397+
select c, cardinality(c), d, cardinality(d) from arrtest;

0 commit comments

Comments
 (0)
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy