index, as described in .
+ You can also search for specific values in an array using the array_offset
+ and array_offsets functions. The former returns the position of
+ the first occurrence of a value in an array; the latter returns an array with the
+ positions of all occurrences of the value in the array. For example:
+
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'mon');
+ array_offset
+--------------
+ 2
+
+SELECT array_offsets(ARRAY[1, 4, 3, 1, 3, 4, 2, 1], 1);
+ array_offsets
+---------------
+ {1,4,8}
+
+
+
Arrays are not sets; searching for specific array elements
+
+
+
+
array_lower('[0:2]={1,2,3}'::int[], 1)
0
+ |
+
+
+ array_offset(anyarray, anyelement , int)
+
+
+ int
+ returns the offset of the first occurrence of the second
+ argument in the array, starting at the element indicated by the third
+ argument or at the first element (array must be one-dimensional)
+ array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'mon')
+ 2
+
+ |
+
+
+ array_offsets(anyarray, anyelement)
+
+
+ int[]
+ returns an array of offsets of all occurrences of the second
+ argument in the array given as first argument (array must be
+ one-dimensional)
+ array_offsets(ARRAY['A','A','B','A'], 'A')
+ {1,2,4}
+
|
+ In array_offset and array_offsets,
+ each array element is compared to the searched value using
+ IS NOT DISTINCT FROM semantics.
+
+
+ In array_offset, NULL is returned
+ if the value is not found.
+
+
+ In array_offsets, NULL is returned
+ only if the array is NULL; if the value is not found in
+ the array, an empty array is returned instead.
+
+
In string_to_array, if the delimiter parameter is
NULL, each character in the input string will become a separate element in
*/
#include "postgres.h"
+#include "catalog/pg_type.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/typcache.h"
+
+
+static Datum array_offset_common(FunctionCallInfo fcinfo);
/*
PG_RETURN_DATUM(result);
}
+
+/*-----------------------------------------------------------------------------
+ * array_offset, array_offset_start :
+ * return the offset of a value in an array.
+ *
+ * IS NOT DISTINCT FROM semantics are used for comparisons. Return NULL when
+ * the value is not found.
+ *-----------------------------------------------------------------------------
+ */
+Datum
+array_offset(PG_FUNCTION_ARGS)
+{
+ return array_offset_common(fcinfo);
+}
+
+Datum
+array_offset_start(PG_FUNCTION_ARGS)
+{
+ return array_offset_common(fcinfo);
+}
+
+/*
+ * array_offset_common
+ * Common code for array_offset and array_offset_start
+ *
+ * These are separate wrappers for the sake of opr_sanity regression test.
+ * They are not strict so we have to test for null inputs explicitly.
+ */
+static Datum
+array_offset_common(FunctionCallInfo fcinfo)
+{
+ ArrayType *array;
+ Oid collation = PG_GET_COLLATION();
+ Oid element_type;
+ Datum searched_element,
+ value;
+ bool isnull;
+ int offset = 0,
+ offset_min;
+ bool found = false;
+ TypeCacheEntry *typentry;
+ ArrayMetaState *my_extra;
+ bool null_search;
+ ArrayIterator array_iterator;
+
+ if (PG_ARGISNULL(0))
+ PG_RETURN_NULL();
+
+ array = PG_GETARG_ARRAYTYPE_P(0);
+ element_type = ARR_ELEMTYPE(array);
+
+ /*
+ * We refuse to search for elements in multi-dimensional arrays, since we
+ * have no good way to report the element's location in the array.
+ */
+ if (ARR_NDIM(array) > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("searching for elements in multidimensional arrays is not supported")));
+
+ if (PG_ARGISNULL(1))
+ {
+ /* fast return when the array doesn't have have nulls */
+ if (!array_contains_nulls(array))
+ PG_RETURN_NULL();
+ searched_element = (Datum) 0;
+ null_search = true;
+ }
+ else
+ {
+ searched_element = PG_GETARG_DATUM(1);
+ null_search = false;
+ }
+
+ /* figure out where to start */
+ if (PG_NARGS() == 3)
+ {
+ if (PG_ARGISNULL(2))
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("initial offset should not be NULL")));
+
+ offset_min = PG_GETARG_INT32(2);
+ }
+ else
+ offset_min = 1;
+
+ /*
+ * We arrange to look up type info for array_create_iterator only once per
+ * series of calls, assuming the element type doesn't change underneath us.
+ */
+ my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
+ if (my_extra == NULL)
+ {
+ fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+ sizeof(ArrayMetaState));
+ my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
+ my_extra->element_type = ~element_type;
+ }
+
+ if (my_extra->element_type != element_type)
+ {
+ get_typlenbyvalalign(element_type,
+ &my_extra->typlen,
+ &my_extra->typbyval,
+ &my_extra->typalign);
+
+ typentry = lookup_type_cache(element_type, TYPECACHE_EQ_OPR_FINFO);
+
+ if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_FUNCTION),
+ errmsg("could not identify an equality operator for type %s",
+ format_type_be(element_type))));
+
+ my_extra->element_type = element_type;
+ fmgr_info(typentry->eq_opr_finfo.fn_oid, &my_extra->proc);
+ }
+
+ /* Examine each array element until we find a match. */
+ array_iterator = array_create_iterator(array, 0, my_extra);
+ while (array_iterate(array_iterator, &value, &isnull))
+ {
+ offset += 1;
+
+ /* skip initial elements if caller requested so */
+ if (offset < offset_min)
+ continue;
+
+ /*
+ * Can't look at the array element's value if it's null; but if we
+ * search for null, we have a hit and are done.
+ */
+ if (isnull || null_search)
+ {
+ if (isnull && null_search)
+ {
+ found = true;
+ break;
+ }
+ else
+ continue;
+ }
+
+ /* not nulls, so run the operator */
+ if (DatumGetBool(FunctionCall2Coll(&my_extra->proc, collation,
+ searched_element, value)))
+ {
+ found = true;
+ break;
+ }
+ }
+
+ array_free_iterator(array_iterator);
+
+ /* Avoid leaking memory when handed toasted input */
+ PG_FREE_IF_COPY(array, 0);
+
+ if (!found)
+ PG_RETURN_NULL();
+
+ PG_RETURN_INT32(offset);
+}
+
+/*-----------------------------------------------------------------------------
+ * array_offsets :
+ * return an array of offsets of a value in an array.
+ *
+ * IS NOT DISTINCT FROM semantics are used for comparisons. Returns NULL when
+ * the input array is NULL. When the value is not found in the array, returns
+ * an empty array.
+ *
+ * This is not strict so we have to test for null inputs explicitly.
+ *-----------------------------------------------------------------------------
+ */
+Datum
+array_offsets(PG_FUNCTION_ARGS)
+{
+ ArrayType *array;
+ Oid collation = PG_GET_COLLATION();
+ Oid element_type;
+ Datum searched_element,
+ value;
+ bool isnull;
+ int offset = 0;
+ TypeCacheEntry *typentry;
+ ArrayMetaState *my_extra;
+ bool null_search;
+ ArrayIterator array_iterator;
+ ArrayBuildState *astate = NULL;
+
+ if (PG_ARGISNULL(0))
+ PG_RETURN_NULL();
+
+ array = PG_GETARG_ARRAYTYPE_P(0);
+ element_type = ARR_ELEMTYPE(array);
+
+ /*
+ * We refuse to search for elements in multi-dimensional arrays, since we
+ * have no good way to report the element's location in the array.
+ */
+ if (ARR_NDIM(array) > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("searching for elements in multidimensional arrays is not supported")));
+
+ astate = initArrayResult(INT4OID, CurrentMemoryContext, false);
+
+ if (PG_ARGISNULL(1))
+ {
+ /* fast return when the array doesn't have have nulls */
+ if (!array_contains_nulls(array))
+ PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
+ searched_element = (Datum) 0;
+ null_search = true;
+ }
+ else
+ {
+ searched_element = PG_GETARG_DATUM(1);
+ null_search = false;
+ }
+
+ /*
+ * We arrange to look up type info for array_create_iterator only once per
+ * series of calls, assuming the element type doesn't change underneath us.
+ */
+ my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
+ if (my_extra == NULL)
+ {
+ fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+ sizeof(ArrayMetaState));
+ my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
+ my_extra->element_type = ~element_type;
+ }
+
+ if (my_extra->element_type != element_type)
+ {
+ get_typlenbyvalalign(element_type,
+ &my_extra->typlen,
+ &my_extra->typbyval,
+ &my_extra->typalign);
+
+ typentry = lookup_type_cache(element_type, TYPECACHE_EQ_OPR_FINFO);
+
+ if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_FUNCTION),
+ errmsg("could not identify an equality operator for type %s",
+ format_type_be(element_type))));
+
+ my_extra->element_type = element_type;
+ fmgr_info(typentry->eq_opr_finfo.fn_oid, &my_extra->proc);
+ }
+
+ /*
+ * Accumulate each array offset iff the element matches the given element.
+ */
+ array_iterator = array_create_iterator(array, 0, my_extra);
+ while (array_iterate(array_iterator, &value, &isnull))
+ {
+ offset += 1;
+
+ /*
+ * Can't look at the array element's value if it's null; but if we
+ * search for null, we have a hit.
+ */
+ if (isnull || null_search)
+ {
+ if (isnull && null_search)
+ astate =
+ accumArrayResult(astate, Int32GetDatum(offset), false,
+ INT4OID, CurrentMemoryContext);
+
+ continue;
+ }
+
+ /* not nulls, so run the operator */
+ if (DatumGetBool(FunctionCall2Coll(&my_extra->proc, collation,
+ searched_element, value)))
+ astate =
+ accumArrayResult(astate, Int32GetDatum(offset), false,
+ INT4OID, CurrentMemoryContext);
+ }
+
+ array_free_iterator(array_iterator);
+
+ /* Avoid leaking memory when handed toasted input */
+ PG_FREE_IF_COPY(array, 0);
+
+ PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
+}
* The passed-in array must remain valid for the lifetime of the iterator.
*/
ArrayIterator
-array_create_iterator(ArrayType *arr, int slice_ndim)
+array_create_iterator(ArrayType *arr, int slice_ndim, ArrayMetaState *mstate)
{
ArrayIterator iterator = palloc0(sizeof(ArrayIteratorData));
iterator->arr = arr;
iterator->nullbitmap = ARR_NULLBITMAP(arr);
iterator->nitems = ArrayGetNItems(ARR_NDIM(arr), ARR_DIMS(arr));
- get_typlenbyvalalign(ARR_ELEMTYPE(arr),
- &iterator->typlen,
- &iterator->typbyval,
- &iterator->typalign);
+
+ if (mstate != NULL)
+ {
+ Assert(mstate->element_type == ARR_ELEMTYPE(arr));
+
+ iterator->typlen = mstate->typlen;
+ iterator->typbyval = mstate->typbyval;
+ iterator->typalign = mstate->typalign;
+ }
+ else
+ get_typlenbyvalalign(ARR_ELEMTYPE(arr),
+ &iterator->typlen,
+ &iterator->typbyval,
+ &iterator->typalign);
/*
* Remember the slicing parameters.
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201503151
+#define CATALOG_VERSION_NO 201503181
#endif
DESCR("larger of two");
DATA(insert OID = 516 ( array_smaller PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 2277 "2277 2277" _null_ _null_ _null_ _null_ array_smaller _null_ _null_ _null_ ));
DESCR("smaller of two");
+DATA(insert OID = 3277 ( array_offset PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 23 "2277 2283" _null_ _null_ _null_ _null_ array_offset _null_ _null_ _null_ ));
+DESCR("returns a offset of value in array");
+DATA(insert OID = 3278 ( array_offset PGNSP PGUID 12 1 0 0 0 f f f f f f i 3 0 23 "2277 2283 23" _null_ _null_ _null_ _null_ array_offset_start _null_ _null_ _null_ ));
+DESCR("returns a offset of value in array with start index");
+DATA(insert OID = 3279 ( array_offsets PGNSP PGUID 12 1 0 0 0 f f f f f f i 2 0 1007 "2277 2283" _null_ _null_ _null_ _null_ array_offsets _null_ _null_ _null_ ));
+DESCR("returns a array of offsets of some value in array");
DATA(insert OID = 1191 ( generate_subscripts PGNSP PGUID 12 1 1000 0 0 f f f f t t i 3 0 23 "2277 23 16" _null_ _null_ _null_ _null_ generate_subscripts _null_ _null_ _null_ ));
DESCR("array subscripts generator");
DATA(insert OID = 1192 ( generate_subscripts PGNSP PGUID 12 1 1000 0 0 f f f f t t i 2 0 23 "2277 23" _null_ _null_ _null_ _null_ generate_subscripts_nodir _null_ _null_ _null_ ));
extern Datum makeArrayResultAny(ArrayBuildStateAny *astate,
MemoryContext rcontext, bool release);
-extern ArrayIterator array_create_iterator(ArrayType *arr, int slice_ndim);
+extern ArrayIterator array_create_iterator(ArrayType *arr, int slice_ndim, ArrayMetaState *mstate);
extern bool array_iterate(ArrayIterator iterator, Datum *value, bool *isnull);
extern void array_free_iterator(ArrayIterator iterator);
extern Datum array_agg_array_transfn(PG_FUNCTION_ARGS);
extern Datum array_agg_array_finalfn(PG_FUNCTION_ARGS);
+extern Datum array_offset(PG_FUNCTION_ARGS);
+extern Datum array_offset_start(PG_FUNCTION_ARGS);
+extern Datum array_offsets(PG_FUNCTION_ARGS);
+
/*
* prototypes for functions defined in array_typanalyze.c
*/
errmsg("FOREACH loop variable must not be of an array type")));
/* Create an iterator to step through the array */
- array_iterator = array_create_iterator(arr, stmt->slice);
+ array_iterator = array_create_iterator(arr, stmt->slice, NULL);
/* Identify iterator result type */
if (stmt->slice > 0)
{{3,4},{5,6},{1,2}}
(1 row)
+SELECT array_offset(ARRAY[1,2,3,4,5], 4);
+ array_offset
+--------------
+ 4
+(1 row)
+
+SELECT array_offset(ARRAY[5,3,4,2,1], 4);
+ array_offset
+--------------
+ 3
+(1 row)
+
+SELECT array_offset(ARRAY[[1,2],[3,4]], 3);
+ERROR: searching for elements in multidimensional arrays is not supported
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'mon');
+ array_offset
+--------------
+ 2
+(1 row)
+
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'sat');
+ array_offset
+--------------
+ 7
+(1 row)
+
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], NULL);
+ array_offset
+--------------
+
+(1 row)
+
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu',NULL,'fri','sat'], NULL);
+ array_offset
+--------------
+ 6
+(1 row)
+
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu',NULL,'fri','sat'], 'sat');
+ array_offset
+--------------
+ 8
+(1 row)
+
+SELECT array_offsets(NULL, 10);
+ array_offsets
+---------------
+
+(1 row)
+
+SELECT array_offsets(NULL, NULL::int);
+ array_offsets
+---------------
+
+(1 row)
+
+SELECT array_offsets(ARRAY[1,2,3,4,5,6,1,2,3,4,5,6], 4);
+ array_offsets
+---------------
+ {4,10}
+(1 row)
+
+SELECT array_offsets(ARRAY[[1,2],[3,4]], 4);
+ERROR: searching for elements in multidimensional arrays is not supported
+SELECT array_offsets(ARRAY[1,2,3,4,5,6,1,2,3,4,5,6], NULL);
+ array_offsets
+---------------
+ {}
+(1 row)
+
+SELECT array_offsets(ARRAY[1,2,3,NULL,5,6,1,2,3,NULL,5,6], NULL);
+ array_offsets
+---------------
+ {4,10}
+(1 row)
+
+SELECT array_length(array_offsets(ARRAY(SELECT 'AAAAAAAAAAAAAAAAAAAAAAAAA'::text || i % 10
+ FROM generate_series(1,100) g(i)),
+ 'AAAAAAAAAAAAAAAAAAAAAAAAA5'), 1);
+ array_length
+--------------
+ 10
+(1 row)
+
+DO $$
+DECLARE
+ o int;
+ a int[] := ARRAY[1,2,3,2,3,1,2];
+BEGIN
+ o := array_offset(a, 2);
+ WHILE o IS NOT NULL
+ LOOP
+ RAISE NOTICE '%', o;
+ o := array_offset(a, 2, o + 1);
+ END LOOP;
+END
+$$ LANGUAGE plpgsql;
+NOTICE: 2
+NOTICE: 4
+NOTICE: 7
-- operators
SELECT a FROM arrtest WHERE b = ARRAY[[[113,142],[1,147]]];
a
SELECT array_cat(ARRAY[1,2], ARRAY[[3,4],[5,6]]) AS "{{1,2},{3,4},{5,6}}";
SELECT array_cat(ARRAY[[3,4],[5,6]], ARRAY[1,2]) AS "{{3,4},{5,6},{1,2}}";
+SELECT array_offset(ARRAY[1,2,3,4,5], 4);
+SELECT array_offset(ARRAY[5,3,4,2,1], 4);
+SELECT array_offset(ARRAY[[1,2],[3,4]], 3);
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'mon');
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'sat');
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu','fri','sat'], NULL);
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu',NULL,'fri','sat'], NULL);
+SELECT array_offset(ARRAY['sun','mon','tue','wed','thu',NULL,'fri','sat'], 'sat');
+
+SELECT array_offsets(NULL, 10);
+SELECT array_offsets(NULL, NULL::int);
+SELECT array_offsets(ARRAY[1,2,3,4,5,6,1,2,3,4,5,6], 4);
+SELECT array_offsets(ARRAY[[1,2],[3,4]], 4);
+SELECT array_offsets(ARRAY[1,2,3,4,5,6,1,2,3,4,5,6], NULL);
+SELECT array_offsets(ARRAY[1,2,3,NULL,5,6,1,2,3,NULL,5,6], NULL);
+SELECT array_length(array_offsets(ARRAY(SELECT 'AAAAAAAAAAAAAAAAAAAAAAAAA'::text || i % 10
+ FROM generate_series(1,100) g(i)),
+ 'AAAAAAAAAAAAAAAAAAAAAAAAA5'), 1);
+
+DO $$
+DECLARE
+ o int;
+ a int[] := ARRAY[1,2,3,2,3,1,2];
+BEGIN
+ o := array_offset(a, 2);
+ WHILE o IS NOT NULL
+ LOOP
+ RAISE NOTICE '%', o;
+ o := array_offset(a, 2, o + 1);
+ END LOOP;
+END
+$$ LANGUAGE plpgsql;
+
-- operators
SELECT a FROM arrtest WHERE b = ARRAY[[[113,142],[1,147]]];
SELECT NOT ARRAY[1.1,1.2,1.3] = ARRAY[1.1,1.2,1.3] AS "FALSE";
projects / postgresql.git / commitdiff