</sect1>
<sect1 id="functions-comparison">
- <title>Comparison Operators</title>
+ <title>Comparison Functions and Operators</title>
<indexterm zone="functions-comparison">
<primary>comparison</primary>
</indexterm>
<para>
- The usual comparison operators are available, shown in <xref
- linkend="functions-comparison-table">.
+ The usual comparison operators are available, as shown in <xref
+ linkend="functions-comparison-op-table">.
</para>
- <table id="functions-comparison-table">
+ <table id="functions-comparison-op-table">
<title>Comparison Operators</title>
<tgroup cols="2">
<thead>
</para>
-->
+ <para>
+ Some comparison-related functions are also available, as shown in <xref
+ linkend="functions-comparison-func-table">.
+ </para>
+
+ <table id="functions-comparison-func-table">
+ <title>Comparison Functions</title>
+ <tgroup cols="4">
+ <thead>
+ <row>
+ <entry>Function</entry>
+ <entry>Description</entry>
+ <entry>Example</entry>
+ <entry>Example Result</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <indexterm>
+ <primary>num_nonnulls</primary>
+ </indexterm>
+ <literal>num_nonnulls(VARIADIC "any")</literal>
+ </entry>
+ <entry>returns the number of non-NULL arguments</entry>
+ <entry><literal>num_nonnulls(1, NULL, 2)</literal></entry>
+ <entry><literal>2</literal></entry>
+ </row>
+ <row>
+ <entry>
+ <indexterm>
+ <primary>num_nulls</primary>
+ </indexterm>
+ <literal>num_nulls(VARIADIC "any")</literal>
+ </entry>
+ <entry>returns the number of NULL arguments</entry>
+ <entry><literal>num_nulls(1, NULL, 2)</literal></entry>
+ <entry><literal>1</literal></entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
</sect1>
<sect1 id="functions-math">
</note>
<para>
The standard comparison operators shown in <xref
- linkend="functions-comparison-table"> are available for
+ linkend="functions-comparison-op-table"> are available for
<type>jsonb</type>, but not for <type>json</type>. They follow the
ordering rules for B-tree operations outlined at <xref
linkend="json-indexing">.
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
+/*
+ * Common subroutine for num_nulls() and num_nonnulls().
+ * Returns TRUE if successful, FALSE if function should return NULL.
+ * If successful, total argument count and number of nulls are
+ * returned into *nargs and *nulls.
+ */
+static bool
+count_nulls(FunctionCallInfo fcinfo,
+ int32 *nargs, int32 *nulls)
+{
+ int32 count = 0;
+ int i;
+
+ /* Did we get a VARIADIC array argument, or separate arguments? */
+ if (get_fn_expr_variadic(fcinfo->flinfo))
+ {
+ ArrayType *arr;
+ int ndims,
+ nitems,
+ *dims;
+ bits8 *bitmap;
+
+ Assert(PG_NARGS() == 1);
+
+ /*
+ * If we get a null as VARIADIC array argument, we can't say anything
+ * useful about the number of elements, so return NULL. This behavior
+ * is consistent with other variadic functions - see concat_internal.
+ */
+ if (PG_ARGISNULL(0))
+ return false;
+
+ /*
+ * Non-null argument had better be an array. We assume that any call
+ * context that could let get_fn_expr_variadic return true will have
+ * checked that a VARIADIC-labeled parameter actually is an array. So
+ * it should be okay to just Assert that it's an array rather than
+ * doing a full-fledged error check.
+ */
+ Assert(OidIsValid(get_base_element_type(get_fn_expr_argtype(fcinfo->flinfo, 0))));
+
+ /* OK, safe to fetch the array value */
+ arr = PG_GETARG_ARRAYTYPE_P(0);
+
+ /* Count the array elements */
+ ndims = ARR_NDIM(arr);
+ dims = ARR_DIMS(arr);
+ nitems = ArrayGetNItems(ndims, dims);
+
+ /* Count those that are NULL */
+ bitmap = ARR_NULLBITMAP(arr);
+ if (bitmap)
+ {
+ int bitmask = 1;
+
+ for (i = 0; i < nitems; i++)
+ {
+ if ((*bitmap & bitmask) == 0)
+ count++;
+
+ bitmask <<= 1;
+ if (bitmask == 0x100)
+ {
+ bitmap++;
+ bitmask = 1;
+ }
+ }
+ }
+
+ *nargs = nitems;
+ *nulls = count;
+ }
+ else
+ {
+ /* Separate arguments, so just count 'em */
+ for (i = 0; i < PG_NARGS(); i++)
+ {
+ if (PG_ARGISNULL(i))
+ count++;
+ }
+
+ *nargs = PG_NARGS();
+ *nulls = count;
+ }
+
+ return true;
+}
+
+/*
+ * num_nulls()
+ * Count the number of NULL arguments
+ */
+Datum
+pg_num_nulls(PG_FUNCTION_ARGS)
+{
+ int32 nargs,
+ nulls;
+
+ if (!count_nulls(fcinfo, &nargs, &nulls))
+ PG_RETURN_NULL();
+
+ PG_RETURN_INT32(nulls);
+}
+
+/*
+ * num_nonnulls()
+ * Count the number of non-NULL arguments
+ */
+Datum
+pg_num_nonnulls(PG_FUNCTION_ARGS)
+{
+ int32 nargs,
+ nulls;
+
+ if (!count_nulls(fcinfo, &nargs, &nulls))
+ PG_RETURN_NULL();
+
+ PG_RETURN_INT32(nargs - nulls);
+}
+
+
/*
* current_database()
* Expose the current database to the user
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201602031
+#define CATALOG_VERSION_NO 201602041
#endif
DESCR("hash");
DATA(insert OID = 432 ( hash_numeric PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 23 "1700" _null_ _null_ _null_ _null_ _null_ hash_numeric _null_ _null_ _null_ ));
DESCR("hash");
+
+DATA(insert OID = 438 ( num_nulls PGNSP PGUID 12 1 0 2276 0 f f f f f f i s 1 0 23 "2276" "{2276}" "{v}" _null_ _null_ _null_ pg_num_nulls _null_ _null_ _null_ ));
+DESCR("count the number of NULL arguments");
+DATA(insert OID = 440 ( num_nonnulls PGNSP PGUID 12 1 0 2276 0 f f f f f f i s 1 0 23 "2276" "{2276}" "{v}" _null_ _null_ _null_ pg_num_nonnulls _null_ _null_ _null_ ));
+DESCR("count the number of non-NULL arguments");
+
DATA(insert OID = 458 ( text_larger PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 25 "25 25" _null_ _null_ _null_ _null_ _null_ text_larger _null_ _null_ _null_ ));
DESCR("larger of two");
DATA(insert OID = 459 ( text_smaller PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 25 "25 25" _null_ _null_ _null_ _null_ _null_ text_smaller _null_ _null_ _null_ ));
extern Datum pg_ls_dir_1arg(PG_FUNCTION_ARGS);
/* misc.c */
+extern Datum pg_num_nulls(PG_FUNCTION_ARGS);
+extern Datum pg_num_nonnulls(PG_FUNCTION_ARGS);
extern Datum current_database(PG_FUNCTION_ARGS);
extern Datum current_query(PG_FUNCTION_ARGS);
extern Datum pg_cancel_backend(PG_FUNCTION_ARGS);
extern Datum name_text(PG_FUNCTION_ARGS);
extern Datum text_name(PG_FUNCTION_ARGS);
extern int varstr_cmp(char *arg1, int len1, char *arg2, int len2, Oid collid);
-extern void varstr_sortsupport(SortSupport ssup, Oid collid, bool bpchar);
+extern void varstr_sortsupport(SortSupport ssup, Oid collid, bool bpchar);
extern int varstr_levenshtein(const char *source, int slen,
const char *target, int tlen,
int ins_c, int del_c, int sub_c,
--- /dev/null
+--
+-- num_nulls()
+--
+SELECT num_nonnulls(NULL);
+ num_nonnulls
+--------------
+ 0
+(1 row)
+
+SELECT num_nonnulls('1');
+ num_nonnulls
+--------------
+ 1
+(1 row)
+
+SELECT num_nonnulls(NULL::text);
+ num_nonnulls
+--------------
+ 0
+(1 row)
+
+SELECT num_nonnulls(NULL::text, NULL::int);
+ num_nonnulls
+--------------
+ 0
+(1 row)
+
+SELECT num_nonnulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
+ num_nonnulls
+--------------
+ 4
+(1 row)
+
+SELECT num_nonnulls(VARIADIC '{1,2,NULL,3}'::int[]);
+ num_nonnulls
+--------------
+ 3
+(1 row)
+
+SELECT num_nonnulls(VARIADIC '{"1","2","3","4"}'::text[]);
+ num_nonnulls
+--------------
+ 4
+(1 row)
+
+SELECT num_nonnulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));
+ num_nonnulls
+--------------
+ 99
+(1 row)
+
+SELECT num_nulls(NULL);
+ num_nulls
+-----------
+ 1
+(1 row)
+
+SELECT num_nulls('1');
+ num_nulls
+-----------
+ 0
+(1 row)
+
+SELECT num_nulls(NULL::text);
+ num_nulls
+-----------
+ 1
+(1 row)
+
+SELECT num_nulls(NULL::text, NULL::int);
+ num_nulls
+-----------
+ 2
+(1 row)
+
+SELECT num_nulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
+ num_nulls
+-----------
+ 3
+(1 row)
+
+SELECT num_nulls(VARIADIC '{1,2,NULL,3}'::int[]);
+ num_nulls
+-----------
+ 1
+(1 row)
+
+SELECT num_nulls(VARIADIC '{"1","2","3","4"}'::text[]);
+ num_nulls
+-----------
+ 0
+(1 row)
+
+SELECT num_nulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));
+ num_nulls
+-----------
+ 1
+(1 row)
+
+-- special cases
+SELECT num_nonnulls(VARIADIC NULL::text[]);
+ num_nonnulls
+--------------
+
+(1 row)
+
+SELECT num_nonnulls(VARIADIC '{}'::int[]);
+ num_nonnulls
+--------------
+ 0
+(1 row)
+
+SELECT num_nulls(VARIADIC NULL::text[]);
+ num_nulls
+-----------
+
+(1 row)
+
+SELECT num_nulls(VARIADIC '{}'::int[]);
+ num_nulls
+-----------
+ 0
+(1 row)
+
+-- should fail, one or more arguments is required
+SELECT num_nonnulls();
+ERROR: function num_nonnulls() does not exist
+LINE 1: SELECT num_nonnulls();
+ ^
+HINT: No function matches the given name and argument types. You might need to add explicit type casts.
+SELECT num_nulls();
+ERROR: function num_nulls() does not exist
+LINE 1: SELECT num_nulls();
+ ^
+HINT: No function matches the given name and argument types. You might need to add explicit type casts.
# ----------
# Another group of parallel tests
# ----------
-test: alter_generic alter_operator misc psql async dbsize
+test: alter_generic alter_operator misc psql async dbsize misc_functions
# rules cannot run concurrently with any test that creates a view
test: rules
test: psql
test: async
test: dbsize
+test: misc_functions
test: rules
test: select_views
test: portals_p2
--- /dev/null
+--
+-- num_nulls()
+--
+
+SELECT num_nonnulls(NULL);
+SELECT num_nonnulls('1');
+SELECT num_nonnulls(NULL::text);
+SELECT num_nonnulls(NULL::text, NULL::int);
+SELECT num_nonnulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
+SELECT num_nonnulls(VARIADIC '{1,2,NULL,3}'::int[]);
+SELECT num_nonnulls(VARIADIC '{"1","2","3","4"}'::text[]);
+SELECT num_nonnulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));
+
+SELECT num_nulls(NULL);
+SELECT num_nulls('1');
+SELECT num_nulls(NULL::text);
+SELECT num_nulls(NULL::text, NULL::int);
+SELECT num_nulls(1, 2, NULL::text, NULL::point, '', int8 '9', 1.0 / NULL);
+SELECT num_nulls(VARIADIC '{1,2,NULL,3}'::int[]);
+SELECT num_nulls(VARIADIC '{"1","2","3","4"}'::text[]);
+SELECT num_nulls(VARIADIC ARRAY(SELECT CASE WHEN i <> 40 THEN i END FROM generate_series(1, 100) i));
+
+-- special cases
+SELECT num_nonnulls(VARIADIC NULL::text[]);
+SELECT num_nonnulls(VARIADIC '{}'::int[]);
+SELECT num_nulls(VARIADIC NULL::text[]);
+SELECT num_nulls(VARIADIC '{}'::int[]);
+
+-- should fail, one or more arguments is required
+SELECT num_nonnulls();
+SELECT num_nulls();
projects / postgresql.git / commitdiff