From 55e56c84da99fe7becda2194563f48bb3083c2d1 Mon Sep 17 00:00:00 2001
From: Amit Langote <amitlan@postgresql.org>
Date: Fri, 28 Jun 2024 13:59:57 +0900
Subject: [PATCH] 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
---
doc/src/sgml/func.sgml | 6 +-
src/backend/parser/parse_expr.c | 126 ++++++++++++++++--
src/backend/parser/parse_jsontable.c | 2 +-
.../regress/expected/sqljson_jsontable.out | 26 +++-
.../regress/expected/sqljson_queryfuncs.out | 16 +++
src/test/regress/sql/sqljson_jsontable.sql | 7 +
src/test/regress/sql/sqljson_queryfuncs.sql | 5 +
7 files changed, 174 insertions(+), 14 deletions(-)
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 323098a2377..5a16910d3ca 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -18939,7 +18939,7 @@ DETAIL: Missing "]" after array dimensions.
JSON_TABLE (
<replaceable>context_item</replaceable>, <replaceable>path_expression</replaceable> <optional> AS <replaceable>json_path_name</replaceable> </optional> <optional> PASSING { <replaceable>value</replaceable> AS <replaceable>varname</replaceable> } <optional>, ...</optional> </optional>
COLUMNS ( <replaceable class="parameter">json_table_column</replaceable> <optional>, ...</optional> )
- <optional> { <literal>ERROR</literal> | <literal>EMPTY</literal> } <literal>ON ERROR</literal> </optional>
+ <optional> { <literal>ERROR</literal> | <literal>EMPTY</literal> <optional>ARRAY</optional>} <literal>ON ERROR</literal> </optional>
)
<phrase>
@@ -18951,8 +18951,8 @@ where <replaceable class="parameter">json_table_column</replaceable> is:
<optional> PATH <replaceable>path_expression</replaceable> </optional>
<optional> { WITHOUT | WITH { CONDITIONAL | <optional>UNCONDITIONAL</optional> } } <optional> ARRAY </optional> WRAPPER </optional>
<optional> { KEEP | OMIT } QUOTES <optional> ON SCALAR STRING </optional> </optional>
- <optional> { ERROR | NULL | EMPTY { ARRAY | OBJECT } | DEFAULT <replaceable>expression</replaceable> } ON EMPTY </optional>
- <optional> { ERROR | NULL | EMPTY { ARRAY | OBJECT } | DEFAULT <replaceable>expression</replaceable> } ON ERROR </optional>
+ <optional> { ERROR | NULL | EMPTY { <optional>ARRAY</optional> | OBJECT } | DEFAULT <replaceable>expression</replaceable> } ON EMPTY </optional>
+ <optional> { ERROR | NULL | EMPTY { <optional>ARRAY</optional> | OBJECT } | DEFAULT <replaceable>expression</replaceable> } ON ERROR </optional>
| <replaceable>name</replaceable> <replaceable>type</replaceable> EXISTS <optional> PATH <replaceable>path_expression</replaceable> </optional>
<optional> { ERROR | TRUE | FALSE | UNKNOWN } ON ERROR </optional>
| NESTED <optional> PATH </optional> <replaceable>path_expression</replaceable> <optional> AS <replaceable>json_path_name</replaceable> </optional> COLUMNS ( <replaceable>json_table_column</replaceable> <optional>, ...</optional> )
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 00cd7358ebb..233b7b1cc99 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -4300,14 +4300,124 @@ transformJsonFuncExpr(ParseState *pstate, JsonFuncExpr *func)
}
/* OMIT QUOTES is meaningless when strings are wrapped. */
- if (func->op == JSON_QUERY_OP &&
- func->quotes == JS_QUOTES_OMIT &&
- (func->wrapper == JSW_CONDITIONAL ||
- func->wrapper == JSW_UNCONDITIONAL))
- ereport(ERROR,
- errcode(ERRCODE_SYNTAX_ERROR),
- errmsg("SQL/JSON QUOTES behavior must not be specified when WITH WRAPPER is used"),
- parser_errposition(pstate, func->location));
+ if (func->op == JSON_QUERY_OP)
+ {
+ if (func->quotes == JS_QUOTES_OMIT &&
+ (func->wrapper == JSW_CONDITIONAL ||
+ func->wrapper == JSW_UNCONDITIONAL))
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("SQL/JSON QUOTES behavior must not be specified when WITH WRAPPER is used"),
+ parser_errposition(pstate, func->location));
+ if (func->on_empty != NULL &&
+ func->on_empty->btype != JSON_BEHAVIOR_ERROR &&
+ func->on_empty->btype != JSON_BEHAVIOR_NULL &&
+ func->on_empty->btype != JSON_BEHAVIOR_EMPTY &&
+ func->on_empty->btype != JSON_BEHAVIOR_EMPTY_ARRAY &&
+ func->on_empty->btype != JSON_BEHAVIOR_EMPTY_OBJECT &&
+ func->on_empty->btype != JSON_BEHAVIOR_DEFAULT)
+ {
+ if (func->column_name == NULL)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON EMPTY behavior"),
+ errdetail("Only ERROR, NULL, EMPTY [ ARRAY ], EMPTY OBJECT, or DEFAULT expression is allowed in ON EMPTY for JSON_QUERY()."),
+ parser_errposition(pstate, func->on_empty->location));
+ else
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON EMPTY behavior for column \"%s\"",
+ func->column_name),
+ errdetail("Only ERROR, NULL, EMPTY [ ARRAY ], EMPTY OBJECT, or DEFAULT expression is allowed in ON EMPTY for formatted columns."),
+ parser_errposition(pstate, func->on_empty->location));
+ }
+ if (func->on_error != NULL &&
+ func->on_error->btype != JSON_BEHAVIOR_ERROR &&
+ func->on_error->btype != JSON_BEHAVIOR_NULL &&
+ func->on_error->btype != JSON_BEHAVIOR_EMPTY &&
+ func->on_error->btype != JSON_BEHAVIOR_EMPTY_ARRAY &&
+ func->on_error->btype != JSON_BEHAVIOR_EMPTY_OBJECT &&
+ func->on_error->btype != JSON_BEHAVIOR_DEFAULT)
+ {
+ if (func->column_name == NULL)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON ERROR behavior"),
+ errdetail("Only ERROR, NULL, EMPTY [ ARRAY ], EMPTY OBJECT, or DEFAULT expression is allowed in ON ERROR for JSON_QUERY()."),
+ parser_errposition(pstate, func->on_error->location));
+ else
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON ERROR behavior for column \"%s\"",
+ func->column_name),
+ errdetail("Only ERROR, NULL, EMPTY [ ARRAY ], EMPTY OBJECT, or DEFAULT expression is allowed in ON ERROR for formatted columns."),
+ parser_errposition(pstate, func->on_error->location));
+ }
+ }
+
+ /* Check that ON ERROR/EMPTY behavior values are valid for the function. */
+ if (func->op == JSON_EXISTS_OP &&
+ func->on_error != NULL &&
+ func->on_error->btype != JSON_BEHAVIOR_ERROR &&
+ func->on_error->btype != JSON_BEHAVIOR_TRUE &&
+ func->on_error->btype != JSON_BEHAVIOR_FALSE &&
+ func->on_error->btype != JSON_BEHAVIOR_UNKNOWN)
+ {
+ if (func->column_name == NULL)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON ERROR behavior"),
+ errdetail("Only ERROR, TRUE, FALSE, or UNKNOWN is allowed in ON ERROR for JSON_EXISTS()."),
+ parser_errposition(pstate, func->on_error->location));
+ else
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON ERROR behavior for column \"%s\"",
+ func->column_name),
+ errdetail("Only ERROR, TRUE, FALSE, or UNKNOWN is allowed in ON ERROR for EXISTS columns."),
+ parser_errposition(pstate, func->on_error->location));
+ }
+ if (func->op == JSON_VALUE_OP)
+ {
+ if (func->on_empty != NULL &&
+ func->on_empty->btype != JSON_BEHAVIOR_ERROR &&
+ func->on_empty->btype != JSON_BEHAVIOR_NULL &&
+ func->on_empty->btype != JSON_BEHAVIOR_DEFAULT)
+ {
+ if (func->column_name == NULL)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON EMPTY behavior"),
+ errdetail("Only ERROR, NULL, or DEFAULT expression is allowed in ON EMPTY for JSON_VALUE()."),
+ parser_errposition(pstate, func->on_empty->location));
+ else
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON EMPTY behavior for column \"%s\"",
+ func->column_name),
+ errdetail("Only ERROR, NULL, or DEFAULT expression is allowed in ON EMPTY for scalar columns."),
+ parser_errposition(pstate, func->on_empty->location));
+ }
+ if (func->on_error != NULL &&
+ func->on_error->btype != JSON_BEHAVIOR_ERROR &&
+ func->on_error->btype != JSON_BEHAVIOR_NULL &&
+ func->on_error->btype != JSON_BEHAVIOR_DEFAULT)
+ {
+ if (func->column_name == NULL)
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON ERROR behavior"),
+ errdetail("Only ERROR, NULL, or DEFAULT expression is allowed in ON ERROR for JSON_VALUE()."),
+ parser_errposition(pstate, func->on_error->location));
+ else
+ ereport(ERROR,
+ errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("invalid ON ERROR behavior for column \"%s\"",
+ func->column_name),
+ errdetail("Only ERROR, NULL, or DEFAULT expression is allowed in ON ERROR for scalar columns."),
+ parser_errposition(pstate, func->on_error->location));
+ }
+ }
jsexpr = makeNode(JsonExpr);
jsexpr->location = func->location;
diff --git a/src/backend/parser/parse_jsontable.c b/src/backend/parser/parse_jsontable.c
index b2519c2f329..8a72e498e89 100644
--- a/src/backend/parser/parse_jsontable.c
+++ b/src/backend/parser/parse_jsontable.c
@@ -92,7 +92,7 @@ transformJsonTable(ParseState *pstate, JsonTable *jt)
ereport(ERROR,
errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid ON ERROR behavior"),
- errdetail("Only EMPTY or ERROR is allowed in the top-level ON ERROR clause."),
+ errdetail("Only EMPTY [ ARRAY ] or ERROR is allowed in the top-level ON ERROR clause."),
parser_errposition(pstate, jt->on_error->location));
cxt.pathNameId = 0;
diff --git a/src/test/regress/expected/sqljson_jsontable.out b/src/test/regress/expected/sqljson_jsontable.out
index 73039ea65eb..dfc7182ba9f 100644
--- a/src/test/regress/expected/sqljson_jsontable.out
+++ b/src/test/regress/expected/sqljson_jsontable.out
@@ -9,12 +9,12 @@ SELECT * FROM JSON_TABLE('[]', 'strict $.a' COLUMNS (js2 int PATH '$') DEFAULT 1
ERROR: invalid ON ERROR behavior
LINE 1: ...BLE('[]', 'strict $.a' COLUMNS (js2 int PATH '$') DEFAULT 1 ...
^
-DETAIL: Only EMPTY or ERROR is allowed in the top-level ON ERROR clause.
+DETAIL: Only EMPTY [ ARRAY ] or ERROR is allowed in the top-level ON ERROR clause.
SELECT * FROM JSON_TABLE('[]', 'strict $.a' COLUMNS (js2 int PATH '$') NULL ON ERROR);
ERROR: invalid ON ERROR behavior
LINE 1: ...BLE('[]', 'strict $.a' COLUMNS (js2 int PATH '$') NULL ON ER...
^
-DETAIL: Only EMPTY or ERROR is allowed in the top-level ON ERROR clause.
+DETAIL: Only EMPTY [ ARRAY ] or ERROR is allowed in the top-level ON ERROR clause.
SELECT * FROM JSON_TABLE('[]', 'strict $.a' COLUMNS (js2 int PATH '$') EMPTY ON ERROR);
js2
-----
@@ -1072,3 +1072,25 @@ SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int exists empty object on em
ERROR: syntax error at or near "empty"
LINE 1: ...sonb '1', '$' COLUMNS (a int exists empty object on empty));
^
+-- Test ON ERROR / EMPTY value validity for the function and column types;
+-- all fail
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int) NULL ON ERROR);
+ERROR: invalid ON ERROR behavior
+LINE 1: ... * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int) NULL ON ER...
+ ^
+DETAIL: Only EMPTY [ ARRAY ] or ERROR is allowed in the top-level ON ERROR clause.
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int true on empty));
+ERROR: invalid ON EMPTY behavior for column "a"
+LINE 1: ...T * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int true on em...
+ ^
+DETAIL: Only ERROR, NULL, or DEFAULT expression is allowed in ON EMPTY for scalar columns.
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int omit quotes true on error));
+ERROR: invalid ON ERROR behavior for column "a"
+LINE 1: ...N_TABLE(jsonb '1', '$' COLUMNS (a int omit quotes true on er...
+ ^
+DETAIL: Only ERROR, NULL, EMPTY [ ARRAY ], EMPTY OBJECT, or DEFAULT expression is allowed in ON ERROR for formatted columns.
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int exists empty object on error));
+ERROR: invalid ON ERROR behavior for column "a"
+LINE 1: ...M JSON_TABLE(jsonb '1', '$' COLUMNS (a int exists empty obje...
+ ^
+DETAIL: Only ERROR, TRUE, FALSE, or UNKNOWN is allowed in ON ERROR for EXISTS columns.
diff --git a/src/test/regress/expected/sqljson_queryfuncs.out b/src/test/regress/expected/sqljson_queryfuncs.out
index 9cb250a27a7..6ca17a3d426 100644
--- a/src/test/regress/expected/sqljson_queryfuncs.out
+++ b/src/test/regress/expected/sqljson_queryfuncs.out
@@ -1353,3 +1353,19 @@ SELECT JSON_QUERY(jsonb 'null', '$xyz' PASSING 1 AS xyz);
1
(1 row)
+-- Test ON ERROR / EMPTY value validity for the function; all fail.
+SELECT JSON_EXISTS(jsonb '1', '$' DEFAULT 1 ON ERROR);
+ERROR: invalid ON ERROR behavior
+LINE 1: SELECT JSON_EXISTS(jsonb '1', '$' DEFAULT 1 ON ERROR);
+ ^
+DETAIL: Only ERROR, TRUE, FALSE, or UNKNOWN is allowed in ON ERROR for JSON_EXISTS().
+SELECT JSON_VALUE(jsonb '1', '$' EMPTY ON ERROR);
+ERROR: invalid ON ERROR behavior
+LINE 1: SELECT JSON_VALUE(jsonb '1', '$' EMPTY ON ERROR);
+ ^
+DETAIL: Only ERROR, NULL, or DEFAULT expression is allowed in ON ERROR for JSON_VALUE().
+SELECT JSON_QUERY(jsonb '1', '$' TRUE ON ERROR);
+ERROR: invalid ON ERROR behavior
+LINE 1: SELECT JSON_QUERY(jsonb '1', '$' TRUE ON ERROR);
+ ^
+DETAIL: Only ERROR, NULL, EMPTY [ ARRAY ], EMPTY OBJECT, or DEFAULT expression is allowed in ON ERROR for JSON_QUERY().
diff --git a/src/test/regress/sql/sqljson_jsontable.sql b/src/test/regress/sql/sqljson_jsontable.sql
index bda57981481..f1d99a8a736 100644
--- a/src/test/regress/sql/sqljson_jsontable.sql
+++ b/src/test/regress/sql/sqljson_jsontable.sql
@@ -521,3 +521,10 @@ DROP TABLE s;
-- Prevent ON EMPTY specification on EXISTS columns
SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int exists empty object on empty));
+
+-- Test ON ERROR / EMPTY value validity for the function and column types;
+-- all fail
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int) NULL ON ERROR);
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int true on empty));
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int omit quotes true on error));
+SELECT * FROM JSON_TABLE(jsonb '1', '$' COLUMNS (a int exists empty object on error));
diff --git a/src/test/regress/sql/sqljson_queryfuncs.sql b/src/test/regress/sql/sqljson_queryfuncs.sql
index dc6380141b8..4586fdb8a4e 100644
--- a/src/test/regress/sql/sqljson_queryfuncs.sql
+++ b/src/test/regress/sql/sqljson_queryfuncs.sql
@@ -459,3 +459,8 @@ SELECT json_value('"aaa"', path RETURNING json) FROM jsonpaths;
SELECT JSON_QUERY(jsonb 'null', '$xyz' PASSING 1 AS xy);
SELECT JSON_QUERY(jsonb 'null', '$xy' PASSING 1 AS xyz);
SELECT JSON_QUERY(jsonb 'null', '$xyz' PASSING 1 AS xyz);
+
+-- Test ON ERROR / EMPTY value validity for the function; all fail.
+SELECT JSON_EXISTS(jsonb '1', '$' DEFAULT 1 ON ERROR);
+SELECT JSON_VALUE(jsonb '1', '$' EMPTY ON ERROR);
+SELECT JSON_QUERY(jsonb '1', '$' TRUE ON ERROR);