14 Commits (4d7e24e0f4d05b546228488ccdc2848a80245ffb)

Author	SHA1	Message	Date
Amit Langote	4d7e24e0f4	Revert recent SQL/JSON related commits ... Reverts 68222851d5, 565caaa79a, and 3a97460970, because a few BF animals didn't like one or all of them.	1 year ago
Amit Langote	565caaa79a	SQL/JSON: Fix default ON ERROR behavior for JSON_TABLE ... Use EMPTY ARRAY instead of EMPTY. This change does not affect the runtime behavior of JSON_TABLE(), which continues to return an empty relation ON ERROR. It only alters whether the default ON ERROR behavior is shown in the deparsed output. Reported-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com Backpatch-through: 17	1 year ago
Amit Langote	68222851d5	SQL/JSON: Fix JSON_TABLE() column deparsing ... The deparsing code in get_json_expr_options() unnecessarily emitted the default column-specific ON ERROR / EMPTY behavior when the top-level ON ERROR behavior in JSON_TABLE was set to ERROR. Fix that by not overriding the column-specific default, determined based on the column's JsonExprOp in get_json_table_columns(), with JSON_BEHAVIOR_ERROR when that is the top-level ON ERROR behavior. Note that this only removes redundancy; the current deparsing output is not incorrect, just redundant. Reviewed-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com Backpatch-through: 17	1 year ago
Amit Langote	7f56eaff2f	SQL/JSON: Fix casting for integer EXISTS columns in JSON_TABLE ... The current method of coercing the boolean result value of JsonPathExists() to the target type specified for an EXISTS column, which is to call the type's input function via json_populate_type(), leads to an error when the target type is integer, because the integer input function doesn't recognize boolean literal values as valid. Instead use the boolean-to-integer cast function for coercion in that case so that using integer or domains thereof as type for EXISTS columns works. Note that coercion for ON ERROR values TRUE and FALSE already works like that because the parser creates a cast expression including the cast function, but the coercion of the actual result value is not handled by the parser. Tests by Jian He. Reported-by: Jian He <jian.universality@gmail.com> Author: Jian He <jian.universality@gmail.com> Author: Amit Langote <amitlangote09@gmail.com> Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com Backpatch-through: 17	1 year ago
Amit Langote	74c96699be	SQL/JSON: Some fixes to JsonBehavior expression casting ... 1. Remove the special case handling when casting the JsonBehavior expressions to types with typmod, like 86d33987 did for the casting of SQL/JSON constructor functions. 2. Fix casting for fixed-length character and bit string types by using assignment-level casts. This is again similar to what 86d33987 did, but for ON ERROR / EMPTY expressions. 3. Use runtime coercion for the boolean ON ERROR constants so that using fixed-length character string types, for example, for an EXISTS column doesn't cause a "value too long for type character(n)" when the parser tries to coerce the default ON ERROR value "false" to that type, that is, even when clause is not specified. 4. Simplify the conditions of when to use runtime coercion vs creating the cast expression in the parser itself. jsonb-valued expressions are now always coerced at runtime and boolean expressions too if the target type is a string type for the reasons mentioned above. Tests are taken from a patch that Jian He posted. Reported-by: Jian He <jian.universality@gmail.com> Author: Jian He <jian.universality@gmail.com> Author: Amit Langote <amitlangote09@gmail.com> Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com Backpatch-through: 17	1 year ago
Amit Langote	716bd12d22	SQL/JSON: Always coerce JsonExpr result at runtime ... Instead of looking up casts at parse time for converting the result of JsonPath* query functions to the specified or the default RETURNING type, always perform the conversion at runtime using either the target type's input function or the function json_populate_type(). There are two motivations for this change: 1. json_populate_type() coerces to types with typmod such that any string values that exceed length limit cause an error instead of silent truncation, which is necessary to be standard-conforming. 2. It was possible to end up with a cast expression that doesn't support soft handling of errors causing bugs in the of handling ON ERROR clause. JsonExpr.coercion_expr which would store the cast expression is no longer necessary, so remove. Bump catversion because stored rules change because of the above removal. Reported-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Jian He <jian.universality@gmail.com> Discussion: Discussion: https://postgr.es/m/202405271326.5a5rprki64aw%40alvherre.pgsql	2 years ago
Amit Langote	55e56c84da	SQL/JSON: Validate values in ON ERROR/EMPTY clauses ... Currently, the grammar allows any supported values in the ON ERROR and ON EMPTY clauses for SQL/JSON functions, regardless of whether the values are appropriate for the function. This commit ensures that during parse analysis, the provided value is checked for validity for the given function and throws a syntax error if it is not. While at it, this fixes some omissions in the documentation of the ON ERROR/EMPTY clauses for JSON_TABLE(). Reported-by: Jian He <jian.universality@gmail.com> Reviewed-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/CACJufxFgWGqpESSYzyJ6tSurr3vFYBSNEmCfkGyB_dMdptFnZQ%40mail.gmail.com	2 years ago
Amit Langote	e3c1393efc	SQL/JSON: Prevent ON EMPTY for EXISTS columns in JSON_TABLE() ... Due to an oversight in de3600452b, the ON EMPTY clause was incorrectly allowed in the EXISTS column. Fix the grammar to prevent this. Discussion: https://postgr.es/m/CA%2BHiwqHh3YDXTpccgAo4CdfV9Mhy%2Bmg%3Doh6t8rfM5uLW1BJN4g%40mail.gmail.com	2 years ago
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