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 <[email protected]>
Reviewed-by: Jian He <[email protected]>
Discussion: https://postgr.es/m/CACJufxFgWGqpESSYzyJ6tSurr3vFYBSNEmCfkGyB_dMdptFnZQ%40mail.gmail.com

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 323098a237793b5b6360230404b67d6941a326c0..5a16910d3ca0a034a115c0d556792f84f5127d26 100644 (file)
--- 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 00cd7358ebbe83a48bc38280bca92cd8dfe2974f..233b7b1cc99f186380732ebf935971ac709d291a 100644 (file)
--- 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 b2519c2f329875c54faa1e48460268f36e753f50..8a72e498e89331b4db1cc6ec282d5f0fc227733a 100644 (file)
--- 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 73039ea65ebf01f28831e755dc460df23167ed28..dfc7182ba9fde2dbb29efccbdd60eaed439c7cec 100644 (file)
--- 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 9cb250a27a77ae8cd9f18c7d4f32a19f15e6a0ad..6ca17a3d42614be6fd9004b531f88d36537d0688 100644 (file)
--- 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 bda579814810471c4f5f9efd17b8f8683dde42c8..f1d99a8a7366643d58c9588a051e4d6258b17168 100644 (file)
--- 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 dc6380141b862b9ff5d52f432a49ae7796118f6f..4586fdb8a4e032e791cc6c0d383cfee572abe63a 100644 (file)
--- 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);