From 14801a87769d312dbae1aa0f3552e46c3a804697 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Tue, 4 Nov 2008 14:49:12 +0000
Subject: [PATCH] ADD array_ndims function

Author: Robert Haas <robertmhaas@gmail.com>
---
 doc/src/sgml/func.sgml               | 11 +++++++++++
 src/backend/utils/adt/arrayfuncs.c   | 16 ++++++++++++++++
 src/include/catalog/catversion.h     |  2 +-
 src/include/catalog/pg_proc.h        |  1 +
 src/include/utils/array.h            |  1 +
 src/test/regress/expected/arrays.out |  9 +++++++++
 src/test/regress/sql/arrays.sql      |  3 +++
 7 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 855528a1e3..f257238b99 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -9373,6 +9373,17 @@ SELECT NULLIF(value, '(none)') ...
         <entry><literal>array_cat(ARRAY[1,2,3], ARRAY[4,5])</literal></entry>
         <entry><literal>{1,2,3,4,5}</literal></entry>
        </row>
+       <row>
+        <entry>
+         <literal>
+          <function>array_ndims</function>(<type>anyarray</type>)
+         </literal>
+        </entry>
+        <entry><type>int</type></entry>
+        <entry>returns the number of dimensions of the array</entry>
+        <entry><literal>array_ndims(ARRAY[[1,2,3], [4,5,6]])</literal></entry>
+        <entry><literal>2</literal></entry>
+       </row>
        <row>
         <entry>
          <literal>
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index 98f0f0c222..497d066389 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -1530,6 +1530,22 @@ array_send(PG_FUNCTION_ARGS)
 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
 }
 
+/*
+ * array_ndims :
+ *        returns the number of dimensions of the array pointed to by "v"
+ */
+Datum
+array_ndims(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v = PG_GETARG_ARRAYTYPE_P(0);
+
+	/* Sanity check: does it look like an array at all? */
+	if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT32(ARR_NDIM(v));
+}
+
 /*
  * array_dims :
  *		  returns the dimensions of the array pointed to by "v", as a "text"
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index c3fda2165b..a88d830e7e 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200811031
+#define CATALOG_VERSION_NO	200811041
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 8e1e869a8a..fe20b01e75 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -985,6 +985,7 @@ DATA(insert OID = 393 (  array_le		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2277
 DESCR("array less than or equal");
 DATA(insert OID = 396 (  array_ge		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2277 2277" _null_ _null_ _null_ array_ge _null_ _null_ _null_ ));
 DESCR("array greater than or equal");
+DATA(insert OID = 748 (  array_ndims	   PGNSP PGUID 12 1 0 0 f f t f i 1 23 "2277" _null_ _null_ _null_ array_ndims _null_ _null_ _null_ ));
 DATA(insert OID = 747 (  array_dims		   PGNSP PGUID 12 1 0 0 f f t f i 1 25 "2277" _null_ _null_ _null_ array_dims _null_ _null_ _null_ ));
 DESCR("array dimensions");
 DATA(insert OID = 750 (  array_in		   PGNSP PGUID 12 1 0 0 f f t f s 3 2277 "2275 26 23" _null_ _null_ _null_	array_in _null_ _null_ _null_ ));
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index 05323f083c..500966de65 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -195,6 +195,7 @@ extern Datum btarraycmp(PG_FUNCTION_ARGS);
 extern Datum arrayoverlap(PG_FUNCTION_ARGS);
 extern Datum arraycontains(PG_FUNCTION_ARGS);
 extern Datum arraycontained(PG_FUNCTION_ARGS);
+extern Datum array_ndims(PG_FUNCTION_ARGS);
 extern Datum array_dims(PG_FUNCTION_ARGS);
 extern Datum array_lower(PG_FUNCTION_ARGS);
 extern Datum array_upper(PG_FUNCTION_ARGS);
diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index bcf5280b14..e429995fc8 100644
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -68,6 +68,15 @@ SELECT a[1:3],
  {}         | {}              | {foo,bar} | {}
 (3 rows)
 
+SELECT array_ndims(a) AS a,array_ndims(b) AS b,array_ndims(c) AS c
+   FROM arrtest;
+ a | b | c 
+---+---+---
+ 1 | 3 |  
+ 1 | 2 | 1
+   | 1 | 1
+(3 rows)
+
 SELECT array_dims(a) AS a,array_dims(b) AS b,array_dims(c) AS c
    FROM arrtest;
    a   |        b        |   c   
diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index 868ee4afda..54f8ab53e5 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -53,6 +53,9 @@ SELECT a[1:3],
           d[1:1][1:2]
    FROM arrtest;
 
+SELECT array_ndims(a) AS a,array_ndims(b) AS b,array_ndims(c) AS c
+   FROM arrtest;
+
 SELECT array_dims(a) AS a,array_dims(b) AS b,array_dims(c) AS c
    FROM arrtest;
 
-- 
2.39.5