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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.
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9 files changed

+1813
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‎doc/src/sgml/func.sgml‎

Lines changed: 62 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -10293,6 +10293,32 @@ table2-mapping
1029310293
<entry>Do all of these key/element <emphasis>strings</emphasis> exist?</entry>
1029410294
<entry><literal>'["a", "b"]'::jsonb ?&amp; array['a', 'b']</literal></entry>
1029510295
</row>
10296+
<row>
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<entry><literal>||</literal></entry>
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<entry><type>jsonb</type></entry>
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<entry>Concatentate two jsonb values into a new jsonb value</entry>
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<entry><literal>'["a", "b"]'::jsonb || '["c", "d"]'::jsonb</literal></entry>
10301+
</row>
10302+
<row>
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<entry><literal>-</literal></entry>
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<entry><type>text</type></entry>
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<entry>Delete the field with a specified key, or element with this
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value</entry>
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<entry><literal>'{"a": "b"}'::jsonb - 'a' </literal></entry>
10308+
</row>
10309+
<row>
10310+
<entry><literal>-</literal></entry>
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<entry><type>integer</type></entry>
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<entry>Delete the field or element with specified index (Negative
10313+
integers count from the end)</entry>
10314+
<entry><literal>'["a", "b"]'::jsonb - 1 </literal></entry>
10315+
</row>
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<row>
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<entry><literal>-</literal></entry>
10318+
<entry><type>text[]</type></entry>
10319+
<entry>Delete the field or element with specified path</entry>
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<entry><literal>'["a", {"b":1}]'::jsonb - '{1,b}'::text[] </literal></entry>
10321+
</row>
1029610322
</tbody>
1029710323
</tgroup>
1029810324
</table>
@@ -10803,6 +10829,42 @@ table2-mapping
1080310829
<entry><literal>json_strip_nulls('[{"f1":1,"f2":null},2,null,3]')</literal></entry>
1080410830
<entry><literal>[{"f1":1},2,null,3]</literal></entry>
1080510831
</row>
10832+
<row>
10833+
<entry><para><literal>jsonb_replace(target jsonb, path text[], replacement jsonb)</literal>
10834+
</para></entry>
10835+
<entry><para><type>jsonb</type></para></entry>
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<entry>
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Returns <replaceable>target</replaceable>
10838+
with the section designated by <replaceable>path</replaceable>
10839+
replaced by <replaceable>replacement</replaceable>.
10840+
</entry>
10841+
<entry><literal>jsonb_replace('[{"f1":1,"f2":null},2,null,3]', '{0,f1}','[2,3,4]')</literal></entry>
10842+
<entry><literal>[{"f1":[2,3,4],"f2":null},2,null,3]</literal>
10843+
</entry>
10844+
</row>
10845+
<row>
10846+
<entry><para><literal>jsonb_pretty(from_json jsonb)</literal>
10847+
</para></entry>
10848+
<entry><para><type>text</type></para></entry>
10849+
<entry>
10850+
Returns <replaceable>from_json</replaceable>
10851+
as indented json text.
10852+
</entry>
10853+
<entry><literal>jsonb_pretty('[{"f1":1,"f2":null},2,null,3]')</literal></entry>
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<entry>
10855+
<programlisting>
10856+
[
10857+
{
10858+
"f1": 1,
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"f2": null
10860+
},
10861+
2,
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null,
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3
10864+
]
10865+
</programlisting>
10866+
</entry>
10867+
</row>
1080610868
</tbody>
1080710869
</tgroup>
1080810870
</table>

‎src/backend/utils/adt/jsonb.c‎

Lines changed: 70 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -85,6 +85,8 @@ static void datum_to_jsonb(Datum val, bool is_null, JsonbInState *result,
8585
static void add_jsonb(Datum val, bool is_null, JsonbInState *result,
8686
Oid val_type, bool key_scalar);
8787
static JsonbParseState * clone_parse_state(JsonbParseState * state);
88+
static char *JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent);
89+
static void add_indent(StringInfo out, bool indent, int level);
8890

8991
/*
9092
* jsonb type input function
@@ -421,13 +423,40 @@ jsonb_in_scalar(void *pstate, char *token, JsonTokenType tokentype)
421423
*/
422424
char *
423425
JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
426+
{
427+
return JsonbToCStringWorker(out, in, estimated_len, false);
428+
}
429+
430+
/*
431+
* same thing but with indentation turned on
432+
*/
433+
char *
434+
JsonbToCStringIndent(StringInfo out, JsonbContainer *in, int estimated_len)
435+
{
436+
return JsonbToCStringWorker(out, in, estimated_len, true);
437+
}
438+
439+
/*
440+
* common worker for above two functions
441+
*/
442+
static char *
443+
JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent)
424444
{
425445
bool first = true;
426446
JsonbIterator *it;
427447
JsonbIteratorToken type = WJB_DONE;
428448
JsonbValue v;
429449
int level = 0;
430450
bool redo_switch = false;
451+
/* If we are indenting, don't add a space after a comma */
452+
int ispaces = indent ? 1 : 2;
453+
/*
454+
* Don't indent the very first item. This gets set to the indent flag
455+
* at the bottom of the loop.
456+
*/
457+
bool use_indent = false;
458+
bool raw_scalar = false;
459+
bool last_was_key = false;
431460

432461
if (out == NULL)
433462
out = makeStringInfo();
@@ -444,26 +473,36 @@ JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
444473
{
445474
case WJB_BEGIN_ARRAY:
446475
if (!first)
447-
appendBinaryStringInfo(out, ", ", 2);
448-
first = true;
476+
appendBinaryStringInfo(out, ", ", ispaces);
449477

450478
if (!v.val.array.rawScalar)
451-
appendStringInfoChar(out, '[');
479+
{
480+
add_indent(out, use_indent && !last_was_key, level);
481+
appendStringInfoCharMacro(out, '[');
482+
}
483+
else
484+
raw_scalar = true;
485+
486+
first = true;
452487
level++;
453488
break;
454489
case WJB_BEGIN_OBJECT:
455490
if (!first)
456-
appendBinaryStringInfo(out, ", ", 2);
457-
first = true;
491+
appendBinaryStringInfo(out, ", ", ispaces);
492+
493+
add_indent(out, use_indent && !last_was_key, level);
458494
appendStringInfoCharMacro(out, '{');
459495

496+
first = true;
460497
level++;
461498
break;
462499
case WJB_KEY:
463500
if (!first)
464-
appendBinaryStringInfo(out, ", ", 2);
501+
appendBinaryStringInfo(out, ", ", ispaces);
465502
first = true;
466503

504+
add_indent(out, use_indent, level);
505+
467506
/* json rules guarantee this is a string */
468507
jsonb_put_escaped_value(out, &v);
469508
appendBinaryStringInfo(out, ": ", 2);
@@ -488,33 +527,53 @@ JsonbToCString(StringInfo out, JsonbContainer *in, int estimated_len)
488527
break;
489528
case WJB_ELEM:
490529
if (!first)
491-
appendBinaryStringInfo(out, ", ", 2);
492-
else
493-
first = false;
530+
appendBinaryStringInfo(out, ", ", ispaces);
531+
first = false;
494532

533+
if (! raw_scalar)
534+
add_indent(out, use_indent, level);
495535
jsonb_put_escaped_value(out, &v);
496536
break;
497537
case WJB_END_ARRAY:
498538
level--;
499-
if (!v.val.array.rawScalar)
500-
appendStringInfoChar(out, ']');
539+
if (! raw_scalar)
540+
{
541+
add_indent(out, use_indent, level);
542+
appendStringInfoCharMacro(out, ']');
543+
}
501544
first = false;
502545
break;
503546
case WJB_END_OBJECT:
504547
level--;
548+
add_indent(out, use_indent, level);
505549
appendStringInfoCharMacro(out, '}');
506550
first = false;
507551
break;
508552
default:
509553
elog(ERROR, "unknown jsonb iterator token type");
510554
}
555+
use_indent = indent;
556+
last_was_key = redo_switch;
511557
}
512558

513559
Assert(level == 0);
514560

515561
return out->data;
516562
}
517563

564+
static void
565+
add_indent(StringInfo out, bool indent, int level)
566+
{
567+
if (indent)
568+
{
569+
int i;
570+
571+
appendStringInfoCharMacro(out, '\n');
572+
for (i = 0; i < level; i++)
573+
appendBinaryStringInfo(out, " ", 4);
574+
}
575+
}
576+
518577

519578
/*
520579
* Determine how we want to render values of a given type in datum_to_jsonb.

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