From 6185c9737cf48c9540782d88f12bd2912d6ca1cc Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Thu, 21 Mar 2024 17:06:27 +0900 Subject: Add SQL/JSON query functions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Author: Teodor Sigaev Author: Oleg Bartunov Author: Alexander Korotkov Author: Andrew Dunstan Author: Amit Langote Author: Peter Eisentraut Author: Jian He 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 --- src/backend/nodes/nodeFuncs.c | 159 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) (limited to 'src/backend/nodes/nodeFuncs.c') diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c index 5b702809aec..9f1553bccfa 100644 --- a/src/backend/nodes/nodeFuncs.c +++ b/src/backend/nodes/nodeFuncs.c @@ -236,6 +236,20 @@ exprType(const Node *expr) case T_JsonIsPredicate: type = BOOLOID; break; + case T_JsonExpr: + { + const JsonExpr *jexpr = (const JsonExpr *) expr; + + type = jexpr->returning->typid; + break; + } + case T_JsonBehavior: + { + const JsonBehavior *behavior = (const JsonBehavior *) expr; + + type = exprType(behavior->expr); + break; + } case T_NullTest: type = BOOLOID; break; @@ -495,6 +509,20 @@ exprTypmod(const Node *expr) return exprTypmod((Node *) ((const JsonValueExpr *) expr)->formatted_expr); case T_JsonConstructorExpr: return ((const JsonConstructorExpr *) expr)->returning->typmod; + case T_JsonExpr: + { + const JsonExpr *jexpr = (const JsonExpr *) expr; + + return jexpr->returning->typmod; + } + break; + case T_JsonBehavior: + { + const JsonBehavior *behavior = (const JsonBehavior *) expr; + + return exprTypmod(behavior->expr); + } + break; case T_CoerceToDomain: return ((const CoerceToDomain *) expr)->resulttypmod; case T_CoerceToDomainValue: @@ -974,6 +1002,26 @@ exprCollation(const Node *expr) /* IS JSON's result is boolean ... */ coll = InvalidOid; /* ... so it has no collation */ break; + case T_JsonExpr: + { + const JsonExpr *jsexpr = (JsonExpr *) expr; + + if (jsexpr->coercion_expr) + coll = exprCollation(jsexpr->coercion_expr); + else + coll = jsexpr->collation; + } + break; + case T_JsonBehavior: + { + const JsonBehavior *behavior = (JsonBehavior *) expr; + + if (behavior->expr) + coll = exprCollation(behavior->expr); + else + coll = InvalidOid; + } + break; case T_NullTest: /* NullTest's result is boolean ... */ coll = InvalidOid; /* ... so it has no collation */ @@ -1213,6 +1261,24 @@ exprSetCollation(Node *expr, Oid collation) case T_JsonIsPredicate: Assert(!OidIsValid(collation)); /* result is always boolean */ break; + case T_JsonExpr: + { + JsonExpr *jexpr = (JsonExpr *) expr; + + if (jexpr->coercion_expr) + exprSetCollation((Node *) jexpr->coercion_expr, collation); + else + jexpr->collation = collation; + } + break; + case T_JsonBehavior: + { + JsonBehavior *behavior = (JsonBehavior *) expr; + + if (behavior->expr) + exprSetCollation(behavior->expr, collation); + } + break; case T_NullTest: /* NullTest's result is boolean ... */ Assert(!OidIsValid(collation)); /* ... so never set a collation */ @@ -1519,6 +1585,18 @@ exprLocation(const Node *expr) case T_JsonIsPredicate: loc = ((const JsonIsPredicate *) expr)->location; break; + case T_JsonExpr: + { + const JsonExpr *jsexpr = (const JsonExpr *) expr; + + /* consider both function name and leftmost arg */ + loc = leftmostLoc(jsexpr->location, + exprLocation(jsexpr->formatted_expr)); + } + break; + case T_JsonBehavior: + loc = exprLocation(((JsonBehavior *) expr)->expr); + break; case T_NullTest: { const NullTest *nexpr = (const NullTest *) expr; @@ -2272,6 +2350,33 @@ expression_tree_walker_impl(Node *node, break; case T_JsonIsPredicate: return WALK(((JsonIsPredicate *) node)->expr); + case T_JsonExpr: + { + JsonExpr *jexpr = (JsonExpr *) node; + + if (WALK(jexpr->formatted_expr)) + return true; + if (WALK(jexpr->path_spec)) + return true; + if (WALK(jexpr->coercion_expr)) + return true; + if (WALK(jexpr->passing_values)) + return true; + /* we assume walker doesn't care about passing_names */ + if (WALK(jexpr->on_empty)) + return true; + if (WALK(jexpr->on_error)) + return true; + } + break; + case T_JsonBehavior: + { + JsonBehavior *behavior = (JsonBehavior *) node; + + if (WALK(behavior->expr)) + return true; + } + break; case T_NullTest: return WALK(((NullTest *) node)->arg); case T_BooleanTest: @@ -3276,6 +3381,32 @@ expression_tree_mutator_impl(Node *node, return (Node *) newnode; } + case T_JsonExpr: + { + JsonExpr *jexpr = (JsonExpr *) node; + JsonExpr *newnode; + + FLATCOPY(newnode, jexpr, JsonExpr); + MUTATE(newnode->formatted_expr, jexpr->formatted_expr, Node *); + MUTATE(newnode->path_spec, jexpr->path_spec, Node *); + MUTATE(newnode->coercion_expr, jexpr->coercion_expr, Node *); + MUTATE(newnode->passing_values, jexpr->passing_values, List *); + /* assume mutator does not care about passing_names */ + MUTATE(newnode->on_empty, jexpr->on_empty, JsonBehavior *); + MUTATE(newnode->on_error, jexpr->on_error, JsonBehavior *); + return (Node *) newnode; + } + break; + case T_JsonBehavior: + { + JsonBehavior *behavior = (JsonBehavior *) node; + JsonBehavior *newnode; + + FLATCOPY(newnode, behavior, JsonBehavior); + MUTATE(newnode->expr, behavior->expr, Node *); + return (Node *) newnode; + } + break; case T_NullTest: { NullTest *ntest = (NullTest *) node; @@ -3965,6 +4096,34 @@ raw_expression_tree_walker_impl(Node *node, break; case T_JsonIsPredicate: return WALK(((JsonIsPredicate *) node)->expr); + case T_JsonArgument: + return WALK(((JsonArgument *) node)->val); + case T_JsonFuncExpr: + { + JsonFuncExpr *jfe = (JsonFuncExpr *) node; + + if (WALK(jfe->context_item)) + return true; + if (WALK(jfe->pathspec)) + return true; + if (WALK(jfe->passing)) + return true; + if (WALK(jfe->output)) + return true; + if (WALK(jfe->on_empty)) + return true; + if (WALK(jfe->on_error)) + return true; + } + break; + case T_JsonBehavior: + { + JsonBehavior *jb = (JsonBehavior *) node; + + if (WALK(jb->expr)) + return true; + } + break; case T_NullTest: return WALK(((NullTest *) node)->arg); case T_BooleanTest: -- cgit v1.2.3