ganeshashree commented on code in PR #58034:
URL: https://github.com/apache/spark/pull/58034#discussion_r4281089216
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/jsonExpressions.scala:
##########
@@ -2272,3 +2331,424 @@ case class JsonTypeof(child: Expression)
override protected def withNewChildInternal(newChild: Expression):
JsonTypeof =
copy(child = newChild)
}
+
+/**
+ * The SQL:2016 `JSON_OBJECT` constructor function (feature T811): constructs
a JSON object from
+ * key-value pairs, written `key VALUE value`, `KEY key VALUE value`, `key :
value`, or the
+ * MySQL-style `key, value`.
+ *
+ * Keys must be non-null strings; a null key is an error. The `ON NULL` clause
controls whether
+ * null-valued pairs are included (NULL ON NULL, the standard default) or
omitted (ABSENT ON NULL).
+ *
+ * A value is spliced in raw (unquoted) when it carries `FORMAT JSON` (tracked
per member by
+ * `rawJson`): the explicit clause (e.g. `JSON_OBJECT('a' VALUE '{"b":1}'
FORMAT JSON)`), or the
+ * implicit form carried by a nested JSON constructor / `JSON_QUERY` under
KEEP QUOTES (see
+ * `rawJsonValue`). Explicit `FORMAT JSON` on a non-constructor is arbitrary
user text, so
+ * `needsValidation` marks it for JSON validation at eval; a nested
constructor is trusted.
+ *
+ * Examples:
+ * JSON_OBJECT('id' VALUE 7, 'name' VALUE 'Ada') ->
'{"id":7,"name":"Ada"}'
+ * JSON_OBJECT('id': 7, 'v': NULL) -> '{"id":7,"v":null}'
+ * JSON_OBJECT('id': 7, 'v': NULL ABSENT ON NULL) -> '{"id":7}'
+ * JSON_OBJECT() -> '{}'
+ *
+ * A clause-free call that is not itself lexically nested in an enclosing
constructor's *value*
+ * position routes through function resolution and is rebuilt by
`JsonObjectExpressionBuilder`, so a
+ * same-named routine can shadow the built-in `json_object`: always for the
comma form (a nested
+ * producer value routes too, carrying its raw-splice eligibility via
`JsonImplicitFormatCarrier`),
+ * but for the `VALUE` / `:` forms only when no member carries a raw value
(`rawJson.contains(true)`
+ * -- an explicit `FORMAT JSON` or a nested producer in *value* position --
keeps it direct).
+ * Otherwise it is built directly from the grammar (clause-bearing, or
value-nested); a nested
+ * *key*-position call stays routable (see `AstBuilder.visitJsonObject`).
+ * The user-facing reference lives in
`docs/sql-ref-syntax-qry-select-json-object.md`.
+ */
+case class JsonObjectExpr(
+ members: Seq[(Expression, Expression)],
+ rawJson: Seq[Boolean],
+ needsValidation: Seq[Boolean],
+ nullBehavior: JsonConstructorNullBehavior =
JsonConstructorNullBehavior.Null,
+ returning: DataType = StringType,
+ timeZoneId: Option[String] = None)
+ extends Expression
+ with TimeZoneAwareExpression
+ with CodegenFallback
Review Comment:
JSON_OBJECT now renders the whole object through a single
JsonObjectEvaluator (one JacksonGenerator lifecycle), via an Invoke like
to_json, and I dropped CodegenFallback so the Project is whole-stage-codegen
eligible again — no more per-member serialization.
On the two scope questions: I added the member-write API to JacksonGenerator
but kept it additive, so to_json, the file writer and Dataset.toJSON are
untouched. I left JSON_ARRAY for the follow-up (SPARK-58730) instead of
diverging it here.
A small JsonObjectKeyGuard keeps the key-before-value null-key ordering, and
the expression stays in the plan (not RuntimeReplaceable) so its
foldable/throwable overrides still gate folding and pushdown.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
