From 1a36bc9dba8eae90963a586d37b6457b32b2fed4 Mon Sep 17 00:00:00 2001 From: Andrew Dunstan Date: Thu, 3 Mar 2022 13:11:14 -0500 Subject: SQL/JSON query functions This introduces the SQL/JSON functions for querying JSON data using jsonpath expressions. The functions are: JSON_EXISTS() JSON_QUERY() JSON_VALUE() All of these functions only operate on jsonb. The workaround for now is to cast the argument to jsonb. JSON_EXISTS() tests if the jsonpath expression applied to the jsonb value yields any values. JSON_VALUE() must return a single value, and an error occurs if it tries to return multiple values. JSON_QUERY() must return a json object or array, and there are various WRAPPER options for handling scalar or multi-value results. Both these functions have options for handling EMPTY and ERROR conditions. 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 --- src/backend/parser/parse_target.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'src/backend/parser/parse_target.c') diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c index e6445c7bafe..62d5d7d4395 100644 --- a/src/backend/parser/parse_target.c +++ b/src/backend/parser/parse_target.c @@ -1971,6 +1971,21 @@ FigureColnameInternal(Node *node, char **name) case T_JsonArrayAgg: *name = "json_arrayagg"; return 2; + case T_JsonFuncExpr: + /* make SQL/JSON functions act like a regular function */ + switch (((JsonFuncExpr *) node)->op) + { + case JSON_QUERY_OP: + *name = "json_query"; + return 2; + case JSON_VALUE_OP: + *name = "json_value"; + return 2; + case JSON_EXISTS_OP: + *name = "json_exists"; + return 2; + } + break; default: break; } -- cgit v1.2.3