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authorAmit Langote <amitlan@postgresql.org>2024-03-21 17:06:27 +0900
committerAmit Langote <amitlan@postgresql.org>2024-03-21 17:07:03 +0900
commit6185c9737cf48c9540782d88f12bd2912d6ca1cc (patch)
tree60b88a5d63fc61a1dbb11c5459ad83273f93db77 /src/backend/utils/adt/formatting.c
parenta145f424d5248a09d766e8cb503b999290cb3b31 (diff)
downloadpostgresql-6185c9737cf48c9540782d88f12bd2912d6ca1cc.tar.gz
postgresql-6185c9737cf48c9540782d88f12bd2912d6ca1cc.zip
Add SQL/JSON query functions
This introduces the following SQL/JSON functions for querying JSON data using jsonpath expressions: JSON_EXISTS(), which can be used to apply a jsonpath expression to a JSON value to check if it yields any values. JSON_QUERY(), which can be used to to apply a jsonpath expression to a JSON value to get a JSON object, an array, or a string. There are various options to control whether multi-value result uses array wrappers and whether the singleton scalar strings are quoted or not. JSON_VALUE(), which can be used to apply a jsonpath expression to a JSON value to return a single scalar value, producing an error if it multiple values are matched. Both JSON_VALUE() and JSON_QUERY() functions have options for handling EMPTY and ERROR conditions, which can be used to specify the behavior when no values are matched and when an error occurs during jsonpath evaluation, respectively. Author: Nikita Glukhov <n.gluhov@postgrespro.ru> Author: Teodor Sigaev <teodor@sigaev.ru> Author: Oleg Bartunov <obartunov@gmail.com> Author: Alexander Korotkov <aekorotkov@gmail.com> Author: Andrew Dunstan <andrew@dunslane.net> Author: Amit Langote <amitlangote09@gmail.com> Author: Peter Eisentraut <peter@eisentraut.org> Author: Jian He <jian.universality@gmail.com> Reviewers have included (in no particular order): Andres Freund, Alexander Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu, Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby, Álvaro Herrera, Jian He, Anton A. Melnikov, Nikita Malakhov, Peter Eisentraut, Tomas Vondra Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de Discussion: https://postgr.es/m/abd9b83b-aa66-f230-3d6d-734817f0995d%40postgresql.org Discussion: https://postgr.es/m/CA+HiwqHROpf9e644D8BRqYvaAPmgBZVup-xKMDPk-nd4EpgzHw@mail.gmail.com Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com
Diffstat (limited to 'src/backend/utils/adt/formatting.c')
-rw-r--r--src/backend/utils/adt/formatting.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 8160d78ec6d..79df80704d7 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4584,6 +4584,50 @@ parse_datetime(text *date_txt, text *fmt, Oid collid, bool strict,
}
/*
+ * Parses the datetime format string in 'fmt_str' and returns true if it
+ * contains a timezone specifier, false if not.
+ */
+bool
+datetime_format_has_tz(const char *fmt_str)
+{
+ bool incache;
+ int fmt_len = strlen(fmt_str);
+ int result;
+ FormatNode *format;
+
+ if (fmt_len > DCH_CACHE_SIZE)
+ {
+ /*
+ * Allocate new memory if format picture is bigger than static cache
+ * and do not use cache (call parser always)
+ */
+ incache = false;
+
+ format = (FormatNode *) palloc((fmt_len + 1) * sizeof(FormatNode));
+
+ parse_format(format, fmt_str, DCH_keywords,
+ DCH_suff, DCH_index, DCH_FLAG, NULL);
+ }
+ else
+ {
+ /*
+ * Use cache buffers
+ */
+ DCHCacheEntry *ent = DCH_cache_fetch(fmt_str, false);
+
+ incache = true;
+ format = ent->format;
+ }
+
+ result = DCH_datetime_type(format);
+
+ if (!incache)
+ pfree(format);
+
+ return result & DCH_ZONED;
+}
+
+/*
* do_to_timestamp: shared code for to_timestamp and to_date
*
* Parse the 'date_txt' according to 'fmt', return results as a struct pg_tm,