Add a non-strict version of jsonb_set

jsonb_set_lax() is the same as jsonb_set, except that it takes and extra
argument that specifies what to do if the value argument is NULL. The
default is 'use_json_null'. Other possibilities are 'raise_exception',
'return_target' and 'delete_key', all these behaviours having been
suggested as reasonable by various users.

Discussion: https://postgr.es/m/375873e2-c957-3a8d-64f9-26c43c2b16e7@2ndQuadrant.com

Reviewed by: Pavel Stehule

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 4b42f12862587e9e033ff11cb4426acad31da2d4..72072e754592ae4438ac26526f3b4a8b331b4b97 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -12231,6 +12231,9 @@ table2-mapping
   <indexterm>
    <primary>jsonb_set</primary>
   </indexterm>
+  <indexterm>
+   <primary>jsonb_set_lax</primary>
+  </indexterm>
   <indexterm>
    <primary>jsonb_insert</primary>
   </indexterm>
@@ -12545,6 +12548,26 @@ table2-mapping
          </para><para><literal>[{"f1": 1, "f2": null, "f3": [2, 3, 4]}, 2]</literal>
         </para></entry>
        </row>
+      <row>
+       <entry><para><literal>jsonb_set_lax(target jsonb, path text[], new_value jsonb <optional>, create_missing boolean</optional> <optional>, null_value_treatment text</optional>)</literal>
+         </para></entry>
+       <entry><para><type>jsonb</type></para></entry>
+       <entry>
+        If <replaceable>new_value</replaceable> is not <literal>null</literal>,
+        behaves identically to <literal>jsonb_set</literal>. Otherwise behaves
+        according to the value of <replaceable>null_value_treatment</replaceable>
+        which must be one of <literal>'raise_exception'</literal>,
+        <literal>'use_json_null'</literal>, <literal>'delete_key'</literal>, or
+        <literal>'return_target'</literal>. The default is
+        <literal>'use_json_null'</literal>.
+       </entry>
+       <entry><para><literal>jsonb_set_lax('[{"f1":1,"f2":null},2,null,3]', '{0,f1}',null)</literal>
+         </para><para><literal>jsonb_set_lax('[{"f1":99,"f2":null},2]', '{0,f3}',null, true, 'return_target')</literal>
+         </para></entry>
+       <entry><para><literal>[{"f1":null,"f2":null},2,null,3]</literal>
+         </para><para><literal>[{"f1": 99, "f2": null}, 2]</literal>
+        </para></entry>
+       </row>
       <row>
        <entry>
            <para><literal>

diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index b3e82de71e643ea1a2fedf5eada1a5dfbbd5d762..c9e75f43705f25aa148f29f873e296f0ca941032 100644 (file)
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1264,6 +1264,15 @@ LANGUAGE INTERNAL
 STRICT IMMUTABLE PARALLEL SAFE
 AS 'jsonb_set';
 
+CREATE OR REPLACE FUNCTION
+  jsonb_set_lax(jsonb_in jsonb, path text[] , replacement jsonb,
+            create_if_missing boolean DEFAULT true,
+            null_value_treatment text DEFAULT 'use_json_null')
+RETURNS jsonb
+LANGUAGE INTERNAL
+CALLED ON NULL INPUT IMMUTABLE PARALLEL SAFE
+AS 'jsonb_set_lax';
+
 CREATE OR REPLACE FUNCTION
   parse_ident(str text, strict boolean DEFAULT true)
 RETURNS text[]

diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index ab5a24a8584a004b485fdd91fea92fa70fc1970a..4b5a0214dca807788fb54bb5ef414f9cc35f57a9 100644 (file)
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -4395,6 +4395,70 @@ jsonb_set(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * SQL function jsonb_set_lax(jsonb, text[], jsonb, boolean, text)
+ */
+Datum
+jsonb_set_lax(PG_FUNCTION_ARGS)
+{
+   /* Jsonb       *in = PG_GETARG_JSONB_P(0); */
+   /* ArrayType  *path = PG_GETARG_ARRAYTYPE_P(1); */
+   /* Jsonb      *newval = PG_GETARG_JSONB_P(2); */
+   /* bool     create = PG_GETARG_BOOL(3); */
+   text       *handle_null;
+   char       *handle_val;
+
+   if (PG_ARGISNULL(0) || PG_ARGISNULL(1) || PG_ARGISNULL(3))
+       PG_RETURN_NULL();
+
+   /* could happen if they pass in an explicit NULL */
+   if (PG_ARGISNULL(4))
+       ereport(ERROR,
+               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                errmsg("need delete_key, return_target, use_json_null, or raise_exception")));
+
+   /* if the new value isn't an SQL NULL just call jsonb_set */
+   if (! PG_ARGISNULL(2))
+       return jsonb_set(fcinfo);
+
+   handle_null = PG_GETARG_TEXT_P(4);
+   handle_val = text_to_cstring(handle_null);
+
+   if (strcmp(handle_val,"raise_exception") == 0)
+   {
+       ereport(ERROR,
+               (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+                errmsg("NULL is not allowed"),
+                errdetail("exception raised due to \"null_value_treatment => 'raise_exception'\""),
+                errhint("to avoid, either change the null_value_treatment argument or ensure that an SQL NULL is not used")));
+   }
+   else if (strcmp(handle_val, "use_json_null") == 0)
+   {
+       Datum     newval;
+
+       newval = DirectFunctionCall1(jsonb_in, CStringGetDatum("null"));
+
+       fcinfo->args[2].value = newval;
+       fcinfo->args[2].isnull = false;
+       return jsonb_set(fcinfo);
+   }
+   else if (strcmp(handle_val, "delete_key") == 0)
+   {
+       return jsonb_delete_path(fcinfo);
+   }
+   else if (strcmp(handle_val, "return_target") == 0)
+   {
+       Jsonb      *in = PG_GETARG_JSONB_P(0);
+       PG_RETURN_JSONB_P(in);
+   }
+   else
+   {
+       ereport(ERROR,
+               (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+                errmsg("need delete_key, return_target, use_json_null, or raise_exception")));
+   }
+}
+
 /*
  * SQL function jsonb_delete_path(jsonb, text[])
  */

diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 427faa3c3b66fbf48d611a8f5d1d036545fe197b..fcf2a1214c4388392c9eb439cca3c565c35f20fd 100644 (file)
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -9305,6 +9305,9 @@
 { oid => '3304',
   proname => 'jsonb_delete_path', prorettype => 'jsonb',
   proargtypes => 'jsonb _text', prosrc => 'jsonb_delete_path' },
+{ oid => '8945', descr => 'Set part of a jsonb, handle NULL value',
+  proname => 'jsonb_set_lax', prorettype => 'jsonb', proisstrict => 'f',
+  proargtypes => 'jsonb _text jsonb bool text', prosrc => 'jsonb_set_lax' },
 { oid => '3305', descr => 'Set part of a jsonb',
   proname => 'jsonb_set', prorettype => 'jsonb',
   proargtypes => 'jsonb _text jsonb bool', prosrc => 'jsonb_set' },

diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index a2a19f81041b6114aa1b99fb69583d6cacab3332..b92f8e8dbc5879fbd9cad0d70496498c63a06545 100644 (file)
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -4511,6 +4511,63 @@ select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, non_integer}', '"new_value"'
 ERROR:  path element at position 3 is not an integer: "non_integer"
 select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, NULL}', '"new_value"');
 ERROR:  path element at position 3 is null
+-- jsonb_set_lax
+\pset null NULL
+-- pass though non nulls to jsonb_set
+select jsonb_set_lax('{"a":1,"b":2}','{b}','5') ;
+  jsonb_set_lax   
+------------------
+ {"a": 1, "b": 5}
+(1 row)
+
+select jsonb_set_lax('{"a":1,"b":2}','{d}','6', true) ;
+      jsonb_set_lax       
+--------------------------
+ {"a": 1, "b": 2, "d": 6}
+(1 row)
+
+-- using the default treatment
+select jsonb_set_lax('{"a":1,"b":2}','{b}',null);
+    jsonb_set_lax    
+---------------------
+ {"a": 1, "b": null}
+(1 row)
+
+select jsonb_set_lax('{"a":1,"b":2}','{d}',null,true);
+        jsonb_set_lax        
+-----------------------------
+ {"a": 1, "b": 2, "d": null}
+(1 row)
+
+-- errors
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, true, null);
+ERROR:  need delete_key, return_target, use_json_null, or raise_exception
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, true, 'no_such_treatment');
+ERROR:  need delete_key, return_target, use_json_null, or raise_exception
+-- explicit treatments
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'raise_exception') as raise_exception;
+ERROR:  NULL is not allowed
+DETAIL:  exception raised due to "null_value_treatment => 'raise_exception'"
+HINT:  to avoid, either change the null_value_treatment argument or ensure that an SQL NULL is not used
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'return_target') as return_target;
+  return_target   
+------------------
+ {"a": 1, "b": 2}
+(1 row)
+
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
+ delete_key 
+------------
+ {"a": 1}
+(1 row)
+
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
+    use_json_null    
+---------------------
+ {"a": 1, "b": null}
+(1 row)
+
+\pset null
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');
          jsonb_insert          

diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index efd4c45185394f349329cd7a60ddd790e3db7689..3e2b8f66df2b20b78d29f45b260d476989ca9acd 100644 (file)
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -1153,6 +1153,26 @@ select jsonb_set('{"a": [1, 2, 3]}', '{a, non_integer}', '"new_value"');
 select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, non_integer}', '"new_value"');
 select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, NULL}', '"new_value"');
 
+-- jsonb_set_lax
+
+\pset null NULL
+
+-- pass though non nulls to jsonb_set
+select jsonb_set_lax('{"a":1,"b":2}','{b}','5') ;
+select jsonb_set_lax('{"a":1,"b":2}','{d}','6', true) ;
+-- using the default treatment
+select jsonb_set_lax('{"a":1,"b":2}','{b}',null);
+select jsonb_set_lax('{"a":1,"b":2}','{d}',null,true);
+-- errors
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, true, null);
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, true, 'no_such_treatment');
+-- explicit treatments
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'raise_exception') as raise_exception;
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'return_target') as return_target;
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'delete_key') as delete_key;
+select jsonb_set_lax('{"a":1,"b":2}', '{b}', null, null_value_treatment => 'use_json_null') as use_json_null;
+
+\pset null
 
 -- jsonb_insert
 select jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"');