Additional functions and operators for jsonb

jsonb_pretty(jsonb) produces nicely indented json output.
jsonb || jsonb concatenates two jsonb values.
jsonb - text removes a key and its associated value from the json
jsonb - int removes the designated array element
jsonb - text[] removes a key and associated value or array element at
the designated path
jsonb_replace(jsonb,text[],jsonb) replaces the array element designated
by the path or the value associated with the key designated by the path
with the given value.

Original work by Dmitry Dolgov, adapted and reworked for PostgreSQL core
by Andrew Dunstan, reviewed and tidied up by Petr Jelinek.

doc/src/sgml/func.sgml

@@ -10293,6 +10293,32 @@ table2-mapping
         <entry>Do all of these key/element <emphasis>strings</emphasis> exist?</entry>
         <entry><literal>'["a", "b"]'::jsonb ?&amp; array['a', 'b']</literal></entry>
        </row>
+       <row>
+        <entry><literal>||</literal></entry>
+        <entry><type>jsonb</type></entry>
+        <entry>Concatentate two jsonb values into a new jsonb value</entry>
+        <entry><literal>'["a", "b"]'::jsonb || '["c", "d"]'::jsonb</literal></entry>
+       </row>
+       <row>
+        <entry><literal>-</literal></entry>
+        <entry><type>text</type></entry>
+        <entry>Delete the field with a specified key, or element with this
+        value</entry>
+        <entry><literal>'{"a": "b"}'::jsonb - 'a' </literal></entry>
+       </row>
+       <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><literal>'["a", "b"]'::jsonb - 1 </literal></entry>
+       </row>
+       <row>
+        <entry><literal>-</literal></entry>
+        <entry><type>text[]</type></entry>
+        <entry>Delete the field or element with specified path</entry>
+        <entry><literal>'["a", {"b":1}]'::jsonb - '{1,b}'::text[] </literal></entry>
+       </row>
       </tbody>
      </tgroup>
    </table>
@@ -10803,6 +10829,42 @@ table2-mapping
        <entry><literal>json_strip_nulls('[{"f1":1,"f2":null},2,null,3]')</literal></entry>
        <entry><literal>[{"f1":1},2,null,3]</literal></entry>
        </row>
+      <row>
+       <entry><para><literal>jsonb_replace(target jsonb, path text[], replacement jsonb)</literal>
+         </para></entry>
+       <entry><para><type>jsonb</type></para></entry>
+       <entry>
+         Returns <replaceable>target</replaceable>
+         with the section designated by  <replaceable>path</replaceable>
+         replaced by <replaceable>replacement</replaceable>.
+       </entry>
+       <entry><literal>jsonb_replace('[{"f1":1,"f2":null},2,null,3]', '{0,f1}','[2,3,4]')</literal></entry>
+       <entry><literal>[{"f1":[2,3,4],"f2":null},2,null,3]</literal>
+        </entry>
+       </row>
+      <row>
+       <entry><para><literal>jsonb_pretty(from_json jsonb)</literal>
+         </para></entry>
+       <entry><para><type>text</type></para></entry>
+       <entry>
+         Returns <replaceable>from_json</replaceable>
+         as indented json text.
+       </entry>
+       <entry><literal>jsonb_pretty('[{"f1":1,"f2":null},2,null,3]')</literal></entry>
+       <entry>
+<programlisting>                    
+ [
+     {
+         "f1": 1,
+         "f2": null
+     },
+     2,
+     null,
+     3
+ ]
+</programlisting>
+        </entry>
+       </row>
      </tbody>
     </tgroup>
    </table>

src/backend/utils/adt/jsonb.c

@@ -85,6 +85,8 @@ static void datum_to_jsonb(Datum val, bool is_null, JsonbInState *result,
 static void add_jsonb(Datum val, bool is_null, JsonbInState *result,
 		  Oid val_type, bool key_scalar);
 static JsonbParseState * clone_parse_state(JsonbParseState * state);
+static char *JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent);
+static void add_indent(StringInfo out, bool indent, int level);
 
 /*
  * jsonb type input function
@@ -421,6 +423,24 @@ jsonb_in_scalar(void *pstate, char *token, JsonTokenType tokentype)
  */
 char *
 JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
+{
+	return JsonbToCStringWorker(out, in, estimated_len, false);
+}
+
+/*
+ * same thing but with indentation turned on
+ */
+char *
+JsonbToCStringIndent(StringInfo out, JsonbContainer *in, int estimated_len)
+{
+	return JsonbToCStringWorker(out, in, estimated_len, true);
+}
+
+/*
+ * common worker for above two functions
+ */
+static char *
+JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent)
 {
 	bool		first = true;
 	JsonbIterator *it;
@@ -428,6 +448,15 @@ JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
 	JsonbValue	v;
 	int			level = 0;
 	bool		redo_switch = false;
+	/* If we are indenting, don't add a space after a comma */
+	int			ispaces = indent ? 1 : 2;
+	/*
+	 * Don't indent the very first item. This gets set to the indent flag
+	 * at the bottom of the loop.
+	 */
+	bool        use_indent = false;
+	bool        raw_scalar = false;
+	bool        last_was_key = false;
 
 	if (out == NULL)
 		out = makeStringInfo();
@@ -444,26 +473,36 @@ JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
 		{
 			case WJB_BEGIN_ARRAY:
 				if (!first)
-					appendBinaryStringInfo(out, ", ", 2);
-				first = true;
+					appendBinaryStringInfo(out, ", ", ispaces);
 
 				if (!v.val.array.rawScalar)
-					appendStringInfoChar(out, '[');
+				{
+					add_indent(out, use_indent && !last_was_key, level);
+					appendStringInfoCharMacro(out, '[');
+				}
+				else
+					raw_scalar = true;
+
+				first = true;
 				level++;
 				break;
 			case WJB_BEGIN_OBJECT:
 				if (!first)
-					appendBinaryStringInfo(out, ", ", 2);
-				first = true;
+					appendBinaryStringInfo(out, ", ", ispaces);
+
+				add_indent(out, use_indent && !last_was_key, level);
 				appendStringInfoCharMacro(out, '{');
 
+				first = true;
 				level++;
 				break;
 			case WJB_KEY:
 				if (!first)
-					appendBinaryStringInfo(out, ", ", 2);
+					appendBinaryStringInfo(out, ", ", ispaces);
 				first = true;
 
+				add_indent(out, use_indent, level);
+
 				/* json rules guarantee this is a string */
 				jsonb_put_escaped_value(out, &v);
 				appendBinaryStringInfo(out, ": ", 2);
@@ -488,26 +527,33 @@ JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
 				break;
 			case WJB_ELEM:
 				if (!first)
-					appendBinaryStringInfo(out, ", ", 2);
-				else
-					first = false;
+					appendBinaryStringInfo(out, ", ", ispaces);
+				first = false;
 
+				if (! raw_scalar)
+					add_indent(out, use_indent, level);
 				jsonb_put_escaped_value(out, &v);
 				break;
 			case WJB_END_ARRAY:
 				level--;
-				if (!v.val.array.rawScalar)
-					appendStringInfoChar(out, ']');
+				if (! raw_scalar)
+				{
+					add_indent(out, use_indent, level);
+					appendStringInfoCharMacro(out, ']');
+				}
 				first = false;
 				break;
 			case WJB_END_OBJECT:
 				level--;
+				add_indent(out, use_indent, level);
 				appendStringInfoCharMacro(out, '}');
 				first = false;
 				break;
 			default:
 				elog(ERROR, "unknown jsonb iterator token type");
 		}
+		use_indent = indent;
+		last_was_key = redo_switch;
 	}
 
 	Assert(level == 0);
@@ -515,6 +561,19 @@ JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
 	return out->data;
 }
 
+static void
+add_indent(StringInfo out, bool indent, int level)
+{
+	if (indent)
+	{
+		int			i;
+
+		appendStringInfoCharMacro(out, '\n');
+		for (i = 0; i < level; i++)
+			appendBinaryStringInfo(out, "    ", 4);
+	}
+}
+
 
 /*
  * Determine how we want to render values of a given type in datum_to_jsonb.

src/include/catalog/pg_operator.h

@@ -1809,6 +1809,14 @@ DATA(insert OID = 3249 (  "?&"	   PGNSP PGUID b f f 3802 1009 16 0 0 jsonb_exist
 DESCR("exists all");
 DATA(insert OID = 3250 (  "<@"	   PGNSP PGUID b f f 3802 3802 16 3246 0 jsonb_contained contsel contjoinsel ));
 DESCR("is contained by");
+DATA(insert OID = 3284 (  "||"	   PGNSP PGUID b f f 3802 3802 3802 0 0 jsonb_concat - - ));
+DESCR("concatenate");
+DATA(insert OID = 3285 (  "-"	   PGNSP PGUID b f f 3802 25 3802 0 0 3302 - - ));
+DESCR("delete");
+DATA(insert OID = 3286 (  "-"	   PGNSP PGUID b f f 3802 23 3802 0 0 3303 - - ));
+DESCR("delete");
+DATA(insert OID = 3287 (  "-"	   PGNSP PGUID b f f 3802 1009 3802 0 0 3304 - - ));
+DESCR("delete");
 
 /*
  * function prototypes

src/include/catalog/pg_proc.h

@@ -4841,7 +4841,14 @@ DATA(insert OID = 3487 (  gin_consistent_jsonb_path  PGNSP PGUID 12 1 0 0 0 f f
 DESCR("GIN support");
 DATA(insert OID = 3489 (  gin_triconsistent_jsonb_path	PGNSP PGUID 12 1 0 0 0 f f f f t f i 7 0 18 "2281 21 2277 23 2281 2281 2281" _null_ _null_ _null_ _null_ _null_ gin_triconsistent_jsonb_path _null_ _null_ _null_ ));
 DESCR("GIN support");
-
+DATA(insert OID = 3301 (  jsonb_concat	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3802 "3802 3802" _null_ _null_ _null_ _null_ _null_ jsonb_concat _null_ _null_ _null_ ));
+DATA(insert OID = 3302 (  jsonb_delete	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3802 "3802 25" _null_ _null_ _null_ _null_ _null_ jsonb_delete _null_ _null_ _null_ ));
+DATA(insert OID = 3303 (  jsonb_delete	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3802 "3802 23" _null_ _null_ _null_ _null_ _null_ jsonb_delete_idx _null_ _null_ _null_ ));
+DATA(insert OID = 3304 (  jsonb_delete	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 3802 "3802 1009" _null_ _null_ _null_ _null_ _null_ jsonb_delete_path _null_ _null_ _null_ ));
+DATA(insert OID = 3305 (  jsonb_replace	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 3 0 3802 "3802 1009 3802" _null_ _null_ _null_ _null_ _null_ jsonb_replace _null_ _null_ _null_ ));
+DESCR("Replace part of a jsonb");
+DATA(insert OID = 3306 (  jsonb_pretty	   PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 25 "3802" _null_ _null_ _null_ _null_ _null_ jsonb_pretty _null_ _null_ _null_ ));
+DESCR("Indented text from jsonb");
 /* txid */
 DATA(insert OID = 2939 (  txid_snapshot_in			PGNSP PGUID 12 1  0 0 0 f f f f t f i 1 0 2970 "2275" _null_ _null_ _null_ _null_ _null_ txid_snapshot_in _null_ _null_ _null_ ));
 DESCR("I/O");

src/include/utils/jsonb.h

@@ -394,6 +394,20 @@ extern Datum gin_extract_jsonb_query_path(PG_FUNCTION_ARGS);
 extern Datum gin_consistent_jsonb_path(PG_FUNCTION_ARGS);
 extern Datum gin_triconsistent_jsonb_path(PG_FUNCTION_ARGS);
 
+/* pretty printer, returns text */
+extern Datum jsonb_pretty(PG_FUNCTION_ARGS);
+
+/* concatenation */
+extern Datum jsonb_concat(PG_FUNCTION_ARGS);
+
+/* deletion */
+Datum jsonb_delete(PG_FUNCTION_ARGS);
+Datum jsonb_delete_idx(PG_FUNCTION_ARGS);
+Datum jsonb_delete_path(PG_FUNCTION_ARGS);
+
+/* replacement */
+extern Datum jsonb_replace(PG_FUNCTION_ARGS);
+
 /* Support functions */
 extern uint32 getJsonbOffset(const JsonbContainer *jc, int index);
 extern uint32 getJsonbLength(const JsonbContainer *jc, int index);
@@ -413,8 +427,11 @@ extern bool JsonbDeepContains(JsonbIterator **val,
 				  JsonbIterator **mContained);
 extern void JsonbHashScalarValue(const JsonbValue *scalarVal, uint32 *hash);
 
-/* jsonb.c support function */
+/* jsonb.c support functions */
 extern char *JsonbToCString(StringInfo out, JsonbContainer *in,
 			   int estimated_len);
+extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
+			   int estimated_len);
+
 
 #endif   /* __JSONB_H__ */

src/test/regress/sql/jsonb.sql

@@ -557,7 +557,7 @@ SELECT count(*) FROM (SELECT j FROM (SELECT * FROM testjsonb UNION ALL SELECT *
 SET enable_hashagg = on;
 SET enable_sort = off;
 SELECT count(*) FROM (SELECT j FROM (SELECT * FROM testjsonb UNION ALL SELECT * FROM testjsonb) js GROUP BY j) js2;
-SELECT distinct * FROM (values (jsonb '{}' || ''),('{}')) v(j);
+SELECT distinct * FROM (values (jsonb '{}' || ''::text),('{}')) v(j);
 SET enable_sort = on;
 
 RESET enable_hashagg;
@@ -684,3 +684,86 @@ select jsonb_strip_nulls('[1,{"a":1,"b":null,"c":2},3]');
 
 -- an empty object is not null and should not be stripped
 select jsonb_strip_nulls('{"a": {"b": null, "c": null}, "d": {} }');
+
+
+select jsonb_pretty('{"a": "test", "b": [1, 2, 3], "c": "test3", "d":{"dd": "test4", "dd2":{"ddd": "test5"}}}');
+select jsonb_pretty('[{"f1":1,"f2":null},2,null,[[{"x":true},6,7],8],3]');
+select jsonb_pretty('{"a":["b", "c"], "d": {"e":"f"}}');
+
+select jsonb_concat('{"d": "test", "a": [1, 2]}', '{"g": "test2", "c": {"c1":1, "c2":2}}');
+
+select '{"aa":1 , "b":2, "cq":3}'::jsonb || '{"cq":"l", "b":"g", "fg":false}';
+select '{"aa":1 , "b":2, "cq":3}'::jsonb || '{"aq":"l"}';
+select '{"aa":1 , "b":2, "cq":3}'::jsonb || '{"aa":"l"}';
+select '{"aa":1 , "b":2, "cq":3}'::jsonb || '{}';
+
+select '["a", "b"]'::jsonb || '["c"]';
+select '["a", "b"]'::jsonb || '["c", "d"]';
+select '["c"]' || '["a", "b"]'::jsonb;
+
+select '["a", "b"]'::jsonb || '"c"';
+select '"c"' || '["a", "b"]'::jsonb;
+
+select '"a"'::jsonb || '{"a":1}';
+select '{"a":1}' || '"a"'::jsonb;
+
+select '["a", "b"]'::jsonb || '{"c":1}';
+select '{"c": 1}'::jsonb || '["a", "b"]';
+
+select '{}'::jsonb || '{"cq":"l", "b":"g", "fg":false}';
+
+select pg_column_size('{}'::jsonb || '{}'::jsonb) = pg_column_size('{}'::jsonb);
+select pg_column_size('{"aa":1}'::jsonb || '{"b":2}'::jsonb) = pg_column_size('{"aa":1, "b":2}'::jsonb);
+select pg_column_size('{"aa":1, "b":2}'::jsonb || '{}'::jsonb) = pg_column_size('{"aa":1, "b":2}'::jsonb);
+select pg_column_size('{}'::jsonb || '{"aa":1, "b":2}'::jsonb) = pg_column_size('{"aa":1, "b":2}'::jsonb);
+
+select jsonb_delete('{"a":1 , "b":2, "c":3}'::jsonb, 'a');
+select jsonb_delete('{"a":null , "b":2, "c":3}'::jsonb, 'a');
+select jsonb_delete('{"a":1 , "b":2, "c":3}'::jsonb, 'b');
+select jsonb_delete('{"a":1 , "b":2, "c":3}'::jsonb, 'c');
+select jsonb_delete('{"a":1 , "b":2, "c":3}'::jsonb, 'd');
+select '{"a":1 , "b":2, "c":3}'::jsonb - 'a'::text;
+select '{"a":null , "b":2, "c":3}'::jsonb - 'a'::text;
+select '{"a":1 , "b":2, "c":3}'::jsonb - 'b'::text;
+select '{"a":1 , "b":2, "c":3}'::jsonb - 'c'::text;
+select '{"a":1 , "b":2, "c":3}'::jsonb - 'd'::text;
+select pg_column_size('{"a":1 , "b":2, "c":3}'::jsonb - 'b'::text) = pg_column_size('{"a":1, "b":2}'::jsonb);
+
+select '["a","b","c"]'::jsonb - 3;
+select '["a","b","c"]'::jsonb - 2;
+select '["a","b","c"]'::jsonb - 1;
+select '["a","b","c"]'::jsonb - 0;
+select '["a","b","c"]'::jsonb - -1;
+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_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '[1,2,3]');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '[1,2,3]');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,1,0}', '[1,2,3]');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,NULL,0}', '[1,2,3]');
+
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '{"1": 2}');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '{"1": 2}');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,1,0}', '{"1": 2}');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,NULL,0}', '{"1": 2}');
+
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '"test"');
+select jsonb_replace('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '{"f": "test"}');
+
+select jsonb_delete('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}', '{n}'::text[]);
+select jsonb_delete('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}', '{b,-1}'::text[]);
+select jsonb_delete('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}', '{d,1,0}'::text[]);
+
+select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb - '{n}'::text[];
+select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb - '{b,-1}'::text[];
+select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb - '{d,1,0}'::text[];