6 Commits (0ad8153c1f4c7129ff19e8a41d142001d35c8514)

Author	SHA1	Message	Date
Amit Langote	03ec203164	SQL/JSON: Correctly enforce the default ON EMPTY behavior ... Currently, when the ON EMPTY clause is not present, the ON ERROR clause (implicit or explicit) dictates the behavior when jsonpath evaluation in ExecEvalJsonExprPath() results in an empty sequence. That is an oversight in the commit 6185c9737c. This commit fixes things so that a NULL is returned instead in that case which is the default behavior when the ON EMPTY clause is not present. Reported-by: Markus Winand Discussion: https://postgr.es/m/F7DD1442-265C-4220-A603-CB0DEB77E91D%40winand.at	2 years ago
Amit Langote	c0fc075186	SQL/JSON: Fix issues with DEFAULT .. ON ERROR / EMPTY ... SQL/JSON query functions allow specifying an expression to return when either of ON ERROR or ON EMPTY condition occurs when evaluating the JSON path expression. The parser (transformJsonBehavior()) checks that the specified expression is one of the supported expressions, but there are two issues with how the check is done that are fixed in this commit: * No check for some expressions related to coercion, such as CoerceViaIO, that may appear in the transformed user-specified expressions that include cast(s) * An unsupported expression may be masked by a coercion-related expression, which must be flagged by checking the latter's argument expression recursively Author: Jian He <jian.universality@gmail.com> Author: Amit Langote <amitlangote09@gmail.com> Reported-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/CACJufxEqhqsfrg_p7EMyo5zak3d767iFDL8vz_4%3DZBHpOtrghw@mail.gmail.com Discussion: https://postgr.es/m/CACJufxGOerH1QJknm1noh-Kz5FqU4p7QfeZSeVT2tN_4SLXYNg@mail.gmail.com	2 years ago
Amit Langote	b4fad46b6b	SQL/JSON: Improve some error messages ... This improves some error messages emitted by SQL/JSON query functions by mentioning column name when available, such as when they are invoked as part of evaluating JSON_TABLE() columns. To do so, a new field column_name is added to both JsonFuncExpr and JsonExpr that is only populated when creating those nodes for transformed JSON_TABLE() columns. While at it, relevant error messages are reworded for clarity. Reported-by: Jian He <jian.universality@gmail.com> Suggested-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/CACJufxG_e0QLCgaELrr2ZNz7AxPeGCNKAORe3fHtFCQLsH4J4Q@mail.gmail.com	2 years ago
Amit Langote	bb766cde63	JSON_TABLE: Add support for NESTED paths and columns ... A NESTED path allows to extract data from nested levels of JSON objects given by the parent path expression, which are projected as columns specified using a nested COLUMNS clause, just like the parent COLUMNS clause. Rows comprised from a NESTED columns are "joined" to the row comprised from the parent columns. If a particular NESTED path evaluates to 0 rows, then the nested COLUMNS will emit NULLs, making it an OUTER join. NESTED columns themselves may include NESTED paths to allow extracting data from arbitrary nesting levels, which are likewise joined against the rows at the parent level. Multiple NESTED paths at a given level are called "sibling" paths and their rows are combined by UNIONing them, that is, after being joined against the parent row as described above. 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: 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 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+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com	2 years ago
Amit Langote	561b74ddb8	Fix restriction on specifying KEEP QUOTES in JSON_QUERY() ... Currently, transformJsonFuncExpr() enforces some restrictions on the combinations of QUOTES and WRAPPER clauses that can be specified in JSON_QUERY(). The intent was to only prevent the useless combination WITH WRAPPER OMIT QUOTES, but the coding prevented KEEP QUOTES too, which is not helpful. Fix that.	2 years ago
Amit Langote	de3600452b	Add basic JSON_TABLE() functionality ... JSON_TABLE() allows JSON data to be converted into a relational view and thus used, for example, in a FROM clause, like other tabular data. Data to show in the view is selected from a source JSON object using a JSON path expression to get a sequence of JSON objects that's called a "row pattern", which becomes the source to compute the SQL/JSON values that populate the view's output columns. Column values themselves are computed using JSON path expressions applied to each of the JSON objects comprising the "row pattern", for which the SQL/JSON query functions added in 6185c9737c are used. To implement JSON_TABLE() as a table function, this augments the TableFunc and TableFuncScanState nodes that are currently used to support XMLTABLE() with some JSON_TABLE()-specific fields. Note that the JSON_TABLE() spec includes NESTED COLUMNS and PLAN clauses, which are required to provide more flexibility to extract data out of nested JSON objects, but they are not implemented here to keep this commit of manageable size. 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: 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 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+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com	2 years ago