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| author | Andrew Dunstan <andrew@dunslane.net> | 2022-03-03 13:02:53 -0500 |
|---|---|---|
| committer | Andrew Dunstan <andrew@dunslane.net> | 2022-03-28 15:37:08 -0400 |
| commit | 33a377608fc29cdd1f6b63be561eab0aee5c81f0 (patch) | |
| tree | 47abccafdaeae1c4466c917bbd85912f39558360 /src/backend/utils/adt/jsonfuncs.c | |
| parent | 6198420ad8a72e37f4fe4964616b17e0fd33b808 (diff) | |
| download | postgresql-33a377608fc29cdd1f6b63be561eab0aee5c81f0.tar.gz postgresql-33a377608fc29cdd1f6b63be561eab0aee5c81f0.zip | |
IS JSON predicate
This patch intrdocuces the SQL standard IS JSON predicate. It operates
on text and bytea values representing JSON as well as on the json and
jsonb types. Each test has an IS and IS NOT variant. The tests are:
IS JSON [VALUE]
IS JSON ARRAY
IS JSON OBJECT
IS JSON SCALAR
IS JSON WITH | WITHOUT UNIQUE KEYS
These are mostly self-explanatory, but note that IS JSON WITHOUT UNIQUE
KEYS is true whenever IS JSON is true, and IS JSON WITH UNIQUE KEYS is
true whenever IS JSON is true except it IS JSON OBJECT is true and there
are duplicate keys (which is never the case when applied to jsonb values).
Nikita Glukhov
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.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
Diffstat (limited to 'src/backend/utils/adt/jsonfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/jsonfuncs.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 29664aa6e40..a24d498b060 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -5528,3 +5528,23 @@ transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype else appendStringInfoString(_state->strval, token); } + +JsonTokenType +json_get_first_token(text *json, bool throw_error) +{ + JsonLexContext *lex; + JsonParseErrorType result; + + lex = makeJsonLexContext(json, false); + + /* Lex exactly one token from the input and check its type. */ + result = json_lex(lex); + + if (result == JSON_SUCCESS) + return lex->token_type; + + if (throw_error) + json_ereport_error(result, lex); + + return JSON_TOKEN_INVALID; /* invalid json */ +} |