Desupport jsonb subscript deletion on objects

Supporting deletion of JSON pairs within jsonb objects using an
array-style integer subscript allowed for surprising outcomes.  This was
mostly due to the implementation-defined ordering of pairs within
objects for jsonb.

It also seems desirable to make jsonb integer subscript deletion
consistent with the 9.4 era general purpose integer subscripting
operator for jsonb (although that operator returns NULL when an object
is encountered, while we prefer here to throw an error).

Peter Geoghegan, following discussion on -hackers.

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1fb9ae217f726a47a2f1433fdf6f2a993cf840fc..2d42b1e1743358cfcf9e096b44808696a0771848 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10309,8 +10309,9 @@ table2-mapping
        <row>
         <entry><literal>-</literal></entry>
         <entry><type>integer</type></entry>
-        <entry>Delete the field or element with specified index (Negative
-        integers count from the end)</entry>
+        <entry>Delete the array element with specified index (Negative
+        integers count from the end).  Throws an error if top level
+        container is not an array.</entry>
         <entry><literal>'["a", "b"]'::jsonb - 1 </literal></entry>
        </row>
        <row>

diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index f87ba77e3ebdb69de55cfdc7a67e34f57c9bb713..c14d3f73fca51aceb0e5a4858993d9225eb0edb7 100644 (file)
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -3400,6 +3400,11 @@ jsonb_delete_idx(PG_FUNCTION_ARGS)
                                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                                 errmsg("cannot delete from scalar")));
 
+       if (JB_ROOT_IS_OBJECT(in))
+               ereport(ERROR,
+                               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                                errmsg("cannot delete from object using integer subscript")));
+
        if (JB_ROOT_COUNT(in) == 0)
                PG_RETURN_JSONB(in);
 

diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 412bf97b83f0461fa84dcc8a3ec9a33506711f10..e6654d47158e2a17d01c2712bb7eca1e171b5de9 100644 (file)
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -3031,54 +3031,6 @@ select '["a","b","c"]'::jsonb - -4;
  ["a", "b", "c"]
 (1 row)
 
-select '{"a":1, "b":2, "c":3}'::jsonb - 3;
-         ?column?         
---------------------------
- {"a": 1, "b": 2, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - 2;
-     ?column?     
-------------------
- {"a": 1, "b": 2}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - 1;
-     ?column?     
-------------------
- {"a": 1, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - 0;
-     ?column?     
-------------------
- {"b": 2, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -1;
-     ?column?     
-------------------
- {"a": 1, "b": 2}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -2;
-     ?column?     
-------------------
- {"a": 1, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -3;
-     ?column?     
-------------------
- {"b": 2, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -4;
-         ?column?         
---------------------------
- {"a": 1, "b": 2, "c": 3}
-(1 row)
-
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '[1,2,3]');
                                 jsonb_set                                 
 --------------------------------------------------------------------------
@@ -3192,12 +3144,8 @@ select '[]'::jsonb - 'a';
 
 select '"a"'::jsonb - 1; -- error
 ERROR:  cannot delete from scalar
-select '{}'::jsonb -  1 ;
- ?column? 
-----------
- {}
-(1 row)
-
+select '{}'::jsonb -  1; -- error
+ERROR:  cannot delete from object using integer subscript
 select '[]'::jsonb - 1;
  ?column? 
 ----------

diff --git a/src/test/regress/expected/jsonb_1.out b/src/test/regress/expected/jsonb_1.out
index 4ead74b572672ad31da2fc2c181a86d3873c012b..0a1ec93456915f2a4d5b59435ef35578694a7d78 100644 (file)
--- a/src/test/regress/expected/jsonb_1.out
+++ b/src/test/regress/expected/jsonb_1.out
@@ -3031,54 +3031,6 @@ select '["a","b","c"]'::jsonb - -4;
  ["a", "b", "c"]
 (1 row)
 
-select '{"a":1, "b":2, "c":3}'::jsonb - 3;
-         ?column?         
---------------------------
- {"a": 1, "b": 2, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - 2;
-     ?column?     
-------------------
- {"a": 1, "b": 2}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - 1;
-     ?column?     
-------------------
- {"a": 1, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - 0;
-     ?column?     
-------------------
- {"b": 2, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -1;
-     ?column?     
-------------------
- {"a": 1, "b": 2}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -2;
-     ?column?     
-------------------
- {"a": 1, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -3;
-     ?column?     
-------------------
- {"b": 2, "c": 3}
-(1 row)
-
-select '{"a":1, "b":2, "c":3}'::jsonb - -4;
-         ?column?         
---------------------------
- {"a": 1, "b": 2, "c": 3}
-(1 row)
-
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '[1,2,3]');
                                 jsonb_set                                 
 --------------------------------------------------------------------------
@@ -3192,12 +3144,8 @@ select '[]'::jsonb - 'a';
 
 select '"a"'::jsonb - 1; -- error
 ERROR:  cannot delete from scalar
-select '{}'::jsonb -  1 ;
- ?column? 
-----------
- {}
-(1 row)
-
+select '{}'::jsonb -  1; -- error
+ERROR:  cannot delete from object using integer subscript
 select '[]'::jsonb - 1;
  ?column? 
 ----------

diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index 2abec221b43bd714415742b8e7765fd15d01663b..29c82a2a62cfea38db9b254ea29489cce66e1a7b 100644 (file)
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -738,15 +738,6 @@ select '["a","b","c"]'::jsonb - -2;
 select '["a","b","c"]'::jsonb - -3;
 select '["a","b","c"]'::jsonb - -4;
 
-select '{"a":1, "b":2, "c":3}'::jsonb - 3;
-select '{"a":1, "b":2, "c":3}'::jsonb - 2;
-select '{"a":1, "b":2, "c":3}'::jsonb - 1;
-select '{"a":1, "b":2, "c":3}'::jsonb - 0;
-select '{"a":1, "b":2, "c":3}'::jsonb - -1;
-select '{"a":1, "b":2, "c":3}'::jsonb - -2;
-select '{"a":1, "b":2, "c":3}'::jsonb - -3;
-select '{"a":1, "b":2, "c":3}'::jsonb - -4;
-
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '[1,2,3]');
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '[1,2,3]');
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,1,0}', '[1,2,3]');
@@ -775,7 +766,7 @@ select '"a"'::jsonb - 'a'; -- error
 select '{}'::jsonb - 'a';
 select '[]'::jsonb - 'a';
 select '"a"'::jsonb - 1; -- error
-select '{}'::jsonb -  1 ;
+select '{}'::jsonb -  1; -- error
 select '[]'::jsonb - 1;
 select '"a"'::jsonb - '{a}'::text[]; -- error
 select '{}'::jsonb - '{a}'::text[];