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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="FUNCTIONS-JSON"
>9.15. JSON Functions and Operators</A
></H1
><P
> <A
HREF="functions-json.html#FUNCTIONS-JSON-OP-TABLE"
>Table 9-42</A
> shows the operators that
are available for use with the two JSON data types (see <A
HREF="datatype-json.html"
>Section 8.14</A
>).
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-JSON-OP-TABLE"
></A
><P
><B
>Table 9-42. <TT
CLASS="TYPE"
>json</TT
> and <TT
CLASS="TYPE"
>jsonb</TT
> Operators</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><COL><THEAD
><TR
><TH
>Operator</TH
><TH
>Right Operand Type</TH
><TH
>Description</TH
><TH
>Example</TH
><TH
>Example Result</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>-></TT
></TD
><TD
><TT
CLASS="TYPE"
>int</TT
></TD
><TD
>Get JSON array element (indexed from zero, negative
integers count from the end)</TD
><TD
><TT
CLASS="LITERAL"
>'[{"a":"foo"},{"b":"bar"},{"c":"baz"}]'::json->2</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"c":"baz"}</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>-></TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>Get JSON object field by key</TD
><TD
><TT
CLASS="LITERAL"
>'{"a": {"b":"foo"}}'::json->'a'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"b":"foo"}</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>->></TT
></TD
><TD
><TT
CLASS="TYPE"
>int</TT
></TD
><TD
>Get JSON array element as <TT
CLASS="TYPE"
>text</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'[1,2,3]'::json->>2</TT
></TD
><TD
><TT
CLASS="LITERAL"
>3</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>->></TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>Get JSON object field as <TT
CLASS="TYPE"
>text</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'{"a":1,"b":2}'::json->>'b'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>2</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>#></TT
></TD
><TD
><TT
CLASS="TYPE"
>text[]</TT
></TD
><TD
>Get JSON object at specified path</TD
><TD
><TT
CLASS="LITERAL"
>'{"a": {"b":{"c": "foo"}}}'::json#>'{a,b}'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"c": "foo"}</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>#>></TT
></TD
><TD
><TT
CLASS="TYPE"
>text[]</TT
></TD
><TD
>Get JSON object at specified path as <TT
CLASS="TYPE"
>text</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'{"a":[1,2,3],"b":[4,5,6]}'::json#>>'{a,2}'</TT
></TD
><TD
><TT
CLASS="LITERAL"
>3</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> There are parallel variants of these operators for both the
<TT
CLASS="TYPE"
>json</TT
> and <TT
CLASS="TYPE"
>jsonb</TT
> types.
The field/element/path extraction operators
return the same type as their left-hand input (either <TT
CLASS="TYPE"
>json</TT
>
or <TT
CLASS="TYPE"
>jsonb</TT
>), except for those specified as
returning <TT
CLASS="TYPE"
>text</TT
>, which coerce the value to text.
The field/element/path extraction operators return NULL, rather than
failing, if the JSON input does not have the right structure to match
the request; for example if no such element exists. The
field/element/path extraction operators that accept integer JSON
array subscripts all support negative subscripting from the end of
arrays.
</P
></BLOCKQUOTE
></DIV
><P
> The standard comparison operators shown in <A
HREF="functions-comparison.html#FUNCTIONS-COMPARISON-OP-TABLE"
>Table 9-1</A
> are available for
<TT
CLASS="TYPE"
>jsonb</TT
>, but not for <TT
CLASS="TYPE"
>json</TT
>. They follow the
ordering rules for B-tree operations outlined at <A
HREF="datatype-json.html#JSON-INDEXING"
>Section 8.14.4</A
>.
</P
><P
> Some further operators also exist only for <TT
CLASS="TYPE"
>jsonb</TT
>, as shown
in <A
HREF="functions-json.html#FUNCTIONS-JSONB-OP-TABLE"
>Table 9-43</A
>.
Many of these operators can be indexed by
<TT
CLASS="TYPE"
>jsonb</TT
> operator classes. For a full description of
<TT
CLASS="TYPE"
>jsonb</TT
> containment and existence semantics, see <A
HREF="datatype-json.html#JSON-CONTAINMENT"
>Section 8.14.3</A
>. <A
HREF="datatype-json.html#JSON-INDEXING"
>Section 8.14.4</A
>
describes how these operators can be used to effectively index
<TT
CLASS="TYPE"
>jsonb</TT
> data.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-JSONB-OP-TABLE"
></A
><P
><B
>Table 9-43. Additional <TT
CLASS="TYPE"
>jsonb</TT
> Operators</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><THEAD
><TR
><TH
>Operator</TH
><TH
>Right Operand Type</TH
><TH
>Description</TH
><TH
>Example</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>@></TT
></TD
><TD
><TT
CLASS="TYPE"
>jsonb</TT
></TD
><TD
>Does the left JSON value contain the right JSON
path/value entries at the top level?</TD
><TD
><TT
CLASS="LITERAL"
>'{"a":1, "b":2}'::jsonb @> '{"b":2}'::jsonb</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
><@</TT
></TD
><TD
><TT
CLASS="TYPE"
>jsonb</TT
></TD
><TD
>Are the left JSON path/value entries contained at the top level within
the right JSON value?</TD
><TD
><TT
CLASS="LITERAL"
>'{"b":2}'::jsonb <@ '{"a":1, "b":2}'::jsonb</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>?</TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>Does the <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>string</I
></SPAN
> exist as a top-level
key within the JSON value?</TD
><TD
><TT
CLASS="LITERAL"
>'{"a":1, "b":2}'::jsonb ? 'b'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>?|</TT
></TD
><TD
><TT
CLASS="TYPE"
>text[]</TT
></TD
><TD
>Do any of these array <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>strings</I
></SPAN
>
exist as top-level keys?</TD
><TD
><TT
CLASS="LITERAL"
>'{"a":1, "b":2, "c":3}'::jsonb ?| array['b', 'c']</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>?&</TT
></TD
><TD
><TT
CLASS="TYPE"
>text[]</TT
></TD
><TD
>Do all of these array <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>strings</I
></SPAN
> exist
as top-level keys?</TD
><TD
><TT
CLASS="LITERAL"
>'["a", "b"]'::jsonb ?& array['a', 'b']</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>||</TT
></TD
><TD
><TT
CLASS="TYPE"
>jsonb</TT
></TD
><TD
>Concatenate two <TT
CLASS="TYPE"
>jsonb</TT
> values into a new <TT
CLASS="TYPE"
>jsonb</TT
> value</TD
><TD
><TT
CLASS="LITERAL"
>'["a", "b"]'::jsonb || '["c", "d"]'::jsonb</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>-</TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>Delete key/value pair or <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>string</I
></SPAN
>
element from left operand. Key/value pairs are matched based
on their key value.</TD
><TD
><TT
CLASS="LITERAL"
>'{"a": "b"}'::jsonb - 'a' </TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>-</TT
></TD
><TD
><TT
CLASS="TYPE"
>integer</TT
></TD
><TD
>Delete the array element with specified index (Negative
integers count from the end). Throws an error if top level
container is not an array.</TD
><TD
><TT
CLASS="LITERAL"
>'["a", "b"]'::jsonb - 1 </TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>#-</TT
></TD
><TD
><TT
CLASS="TYPE"
>text[]</TT
></TD
><TD
>Delete the field or element with specified path (for
JSON arrays, negative integers count from the end)</TD
><TD
><TT
CLASS="LITERAL"
>'["a", {"b":1}]'::jsonb #- '{1,b}'</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> The <TT
CLASS="LITERAL"
>||</TT
> operator concatenates two JSON objects by
generating an object containing the union of their keys, taking the
second object's value when there are duplicate keys. All other cases
produce a JSON array: first, any non-array input is converted into a
single-element array, and then the two arrays are concatenated.
It does not operate recursively; only the top-level array or object
structure is merged.
</P
></BLOCKQUOTE
></DIV
><P
> <A
HREF="functions-json.html#FUNCTIONS-JSON-CREATION-TABLE"
>Table 9-44</A
> shows the functions that are
available for creating <TT
CLASS="TYPE"
>json</TT
> and <TT
CLASS="TYPE"
>jsonb</TT
> values.
(There are no equivalent functions for <TT
CLASS="TYPE"
>jsonb</TT
>, of the <TT
CLASS="LITERAL"
>row_to_json</TT
>
and <TT
CLASS="LITERAL"
>array_to_json</TT
> functions. However, the <TT
CLASS="LITERAL"
>to_jsonb</TT
>
function supplies much the same functionality as these functions would.)
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-JSON-CREATION-TABLE"
></A
><P
><B
>Table 9-44. JSON Creation Functions</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><THEAD
><TR
><TH
>Function</TH
><TH
>Description</TH
><TH
>Example</TH
><TH
>Example Result</TH
></TR
></THEAD
><TBODY
><TR
><TD
><P
><TT
CLASS="LITERAL"
>to_json(anyelement)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>to_jsonb(anyelement)</TT
>
</P
></TD
><TD
> Returns the value as <TT
CLASS="TYPE"
>json</TT
> or <TT
CLASS="TYPE"
>jsonb</TT
>.
Arrays and composites are converted
(recursively) to arrays and objects; otherwise, if there is a cast
from the type to <TT
CLASS="TYPE"
>json</TT
>, the cast function will be used to
perform the conversion; otherwise, a scalar value is produced.
For any scalar type other than a number, a Boolean, or a null value,
the text representation will be used, in such a fashion that it is a
valid <TT
CLASS="TYPE"
>json</TT
> or <TT
CLASS="TYPE"
>jsonb</TT
> value.
</TD
><TD
><TT
CLASS="LITERAL"
>to_json('Fred said "Hi."'::text)</TT
></TD
><TD
><TT
CLASS="LITERAL"
>"Fred said \"Hi.\""</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>array_to_json(anyarray [, pretty_bool])</TT
>
</TD
><TD
> Returns the array as a JSON array. A PostgreSQL multidimensional array
becomes a JSON array of arrays. Line feeds will be added between
dimension-1 elements if <TT
CLASS="PARAMETER"
>pretty_bool</TT
> is true.
</TD
><TD
><TT
CLASS="LITERAL"
>array_to_json('{{1,5},{99,100}}'::int[])</TT
></TD
><TD
><TT
CLASS="LITERAL"
>[[1,5],[99,100]]</TT
></TD
></TR
><TR
><TD
> <TT
CLASS="LITERAL"
>row_to_json(record [, pretty_bool])</TT
>
</TD
><TD
> Returns the row as a JSON object. Line feeds will be added between
level-1 elements if <TT
CLASS="PARAMETER"
>pretty_bool</TT
> is true.
</TD
><TD
><TT
CLASS="LITERAL"
>row_to_json(row(1,'foo'))</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"f1":1,"f2":"foo"}</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_build_array(VARIADIC "any")</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_build_array(VARIADIC "any")</TT
>
</P
></TD
><TD
> Builds a possibly-heterogeneously-typed JSON array out of a variadic
argument list.
</TD
><TD
><TT
CLASS="LITERAL"
>json_build_array(1,2,'3',4,5)</TT
></TD
><TD
><TT
CLASS="LITERAL"
>[1, 2, "3", 4, 5]</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_build_object(VARIADIC "any")</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_build_object(VARIADIC "any")</TT
>
</P
></TD
><TD
> Builds a JSON object out of a variadic argument list. By
convention, the argument list consists of alternating
keys and values.
</TD
><TD
><TT
CLASS="LITERAL"
>json_build_object('foo',1,'bar',2)</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"foo": 1, "bar": 2}</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_object(text[])</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_object(text[])</TT
>
</P
></TD
><TD
> Builds a JSON object out of a text array. The array must have either
exactly one dimension with an even number of members, in which case
they are taken as alternating key/value pairs, or two dimensions
such that each inner array has exactly two elements, which
are taken as a key/value pair.
</TD
><TD
><P
><TT
CLASS="LITERAL"
>json_object('{a, 1, b, "def", c, 3.5}')</TT
></P
>
<P
><TT
CLASS="LITERAL"
>json_object('{{a, 1},{b, "def"},{c, 3.5}}')</TT
></P
></TD
><TD
><TT
CLASS="LITERAL"
>{"a": "1", "b": "def", "c": "3.5"}</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_object(keys text[], values text[])</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_object(keys text[], values text[])</TT
>
</P
></TD
><TD
> This form of <CODE
CLASS="FUNCTION"
>json_object</CODE
> takes keys and values pairwise from two separate
arrays. In all other respects it is identical to the one-argument form.
</TD
><TD
><TT
CLASS="LITERAL"
>json_object('{a, b}', '{1,2}')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"a": "1", "b": "2"}</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> <CODE
CLASS="FUNCTION"
>array_to_json</CODE
> and <CODE
CLASS="FUNCTION"
>row_to_json</CODE
> have the same
behavior as <CODE
CLASS="FUNCTION"
>to_json</CODE
> except for offering a pretty-printing
option. The behavior described for <CODE
CLASS="FUNCTION"
>to_json</CODE
> likewise applies
to each individual value converted by the other JSON creation functions.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> The <A
HREF="hstore.html"
>hstore</A
> extension has a cast
from <TT
CLASS="TYPE"
>hstore</TT
> to <TT
CLASS="TYPE"
>json</TT
>, so that
<TT
CLASS="TYPE"
>hstore</TT
> values converted via the JSON creation functions
will be represented as JSON objects, not as primitive string values.
</P
></BLOCKQUOTE
></DIV
><P
> <A
HREF="functions-json.html#FUNCTIONS-JSON-PROCESSING-TABLE"
>Table 9-45</A
> shows the functions that
are available for processing <TT
CLASS="TYPE"
>json</TT
> and <TT
CLASS="TYPE"
>jsonb</TT
> values.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-JSON-PROCESSING-TABLE"
></A
><P
><B
>Table 9-45. JSON Processing Functions</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><COL><THEAD
><TR
><TH
>Function</TH
><TH
>Return Type</TH
><TH
>Description</TH
><TH
>Example</TH
><TH
>Example Result</TH
></TR
></THEAD
><TBODY
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_array_length(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_array_length(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>int</TT
></TD
><TD
> Returns the number of elements in the outermost JSON array.
</TD
><TD
><TT
CLASS="LITERAL"
>json_array_length('[1,2,3,{"f1":1,"f2":[5,6]},4]')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>5</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_each(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_each(jsonb)</TT
>
</P
></TD
><TD
><P
><TT
CLASS="LITERAL"
>setof key text, value json</TT
>
</P
><P
><TT
CLASS="LITERAL"
>setof key text, value jsonb</TT
>
</P
></TD
><TD
> Expands the outermost JSON object into a set of key/value pairs.
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_each('{"a":"foo", "b":"bar"}')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> key | value
-----+-------
a | "foo"
b | "bar"</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_each_text(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_each_text(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>setof key text, value text</TT
></TD
><TD
> Expands the outermost JSON object into a set of key/value pairs. The
returned values will be of type <TT
CLASS="TYPE"
>text</TT
>.
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_each_text('{"a":"foo", "b":"bar"}')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> key | value
-----+-------
a | foo
b | bar</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_extract_path(from_json json, VARIADIC path_elems text[])</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_extract_path(from_json jsonb, VARIADIC path_elems text[])</TT
>
</P
></TD
><TD
><P
><TT
CLASS="TYPE"
>json</TT
></P
><P
><TT
CLASS="TYPE"
>jsonb</TT
>
</P
></TD
><TD
> Returns JSON value pointed to by <TT
CLASS="REPLACEABLE"
><I
>path_elems</I
></TT
>
(equivalent to <TT
CLASS="LITERAL"
>#></TT
> operator).
</TD
><TD
><TT
CLASS="LITERAL"
>json_extract_path('{"f2":{"f3":1},"f4":{"f5":99,"f6":"foo"}}','f4')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>{"f5":99,"f6":"foo"}</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_extract_path_text(from_json json, VARIADIC path_elems text[])</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_extract_path_text(from_json jsonb, VARIADIC path_elems text[])</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
> Returns JSON value pointed to by <TT
CLASS="REPLACEABLE"
><I
>path_elems</I
></TT
>
as <TT
CLASS="TYPE"
>text</TT
>
(equivalent to <TT
CLASS="LITERAL"
>#>></TT
> operator).
</TD
><TD
><TT
CLASS="LITERAL"
>json_extract_path_text('{"f2":{"f3":1},"f4":{"f5":99,"f6":"foo"}}','f4', 'f6')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>foo</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_object_keys(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_object_keys(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>setof text</TT
></TD
><TD
> Returns set of keys in the outermost JSON object.
</TD
><TD
><TT
CLASS="LITERAL"
>json_object_keys('{"f1":"abc","f2":{"f3":"a", "f4":"b"}}')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> json_object_keys
------------------
f1
f2</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_populate_record(base anyelement, from_json json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_populate_record(base anyelement, from_json jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>anyelement</TT
></TD
><TD
> Expands the object in <TT
CLASS="REPLACEABLE"
><I
>from_json</I
></TT
> to a row
whose columns match the record type defined by <TT
CLASS="REPLACEABLE"
><I
>base</I
></TT
>
(see note below).
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_populate_record(null::myrowtype, '{"a":1,"b":2}')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> a | b
---+---
1 | 2</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_populate_recordset(base anyelement, from_json json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_populate_recordset(base anyelement, from_json jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>setof anyelement</TT
></TD
><TD
> Expands the outermost array of objects
in <TT
CLASS="REPLACEABLE"
><I
>from_json</I
></TT
> to a set of rows whose
columns match the record type defined by <TT
CLASS="REPLACEABLE"
><I
>base</I
></TT
> (see
note below).
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_populate_recordset(null::myrowtype, '[{"a":1,"b":2},{"a":3,"b":4}]')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> a | b
---+---
1 | 2
3 | 4</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_array_elements(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_array_elements(jsonb)</TT
>
</P
></TD
><TD
><P
><TT
CLASS="TYPE"
>setof json</TT
>
</P
><P
><TT
CLASS="TYPE"
>setof jsonb</TT
>
</P
></TD
><TD
> Expands a JSON array to a set of JSON values.
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_array_elements('[1,true, [2,false]]')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> value
-----------
1
true
[2,false]</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_array_elements_text(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_array_elements_text(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>setof text</TT
></TD
><TD
> Expands a JSON array to a set of <TT
CLASS="TYPE"
>text</TT
> values.
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_array_elements_text('["foo", "bar"]')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> value
-----------
foo
bar</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_typeof(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_typeof(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
> Returns the type of the outermost JSON value as a text string.
Possible types are
<TT
CLASS="LITERAL"
>object</TT
>, <TT
CLASS="LITERAL"
>array</TT
>, <TT
CLASS="LITERAL"
>string</TT
>, <TT
CLASS="LITERAL"
>number</TT
>,
<TT
CLASS="LITERAL"
>boolean</TT
>, and <TT
CLASS="LITERAL"
>null</TT
>.
</TD
><TD
><TT
CLASS="LITERAL"
>json_typeof('-123.4')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>number</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_to_record(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_to_record(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>record</TT
></TD
><TD
> Builds an arbitrary record from a JSON object (see note below). As
with all functions returning <TT
CLASS="TYPE"
>record</TT
>, the caller must
explicitly define the structure of the record with an <TT
CLASS="LITERAL"
>AS</TT
>
clause.
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_to_record('{"a":1,"b":[1,2,3],"c":"bar"}') as x(a int, b text, d text) </TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> a | b | d
---+---------+---
1 | [1,2,3] |</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_to_recordset(json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_to_recordset(jsonb)</TT
>
</P
></TD
><TD
><TT
CLASS="TYPE"
>setof record</TT
></TD
><TD
> Builds an arbitrary set of records from a JSON array of objects (see
note below). As with all functions returning <TT
CLASS="TYPE"
>record</TT
>, the
caller must explicitly define the structure of the record with
an <TT
CLASS="LITERAL"
>AS</TT
> clause.
</TD
><TD
><TT
CLASS="LITERAL"
>select * from json_to_recordset('[{"a":1,"b":"foo"},{"a":"2","c":"bar"}]') as x(a int, b text);</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
> a | b
---+-----
1 | foo
2 |</PRE
>
</TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>json_strip_nulls(from_json json)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_strip_nulls(from_json jsonb)</TT
>
</P
></TD
><TD
><P
><TT
CLASS="TYPE"
>json</TT
></P
><P
><TT
CLASS="TYPE"
>jsonb</TT
></P
></TD
><TD
> Returns <TT
CLASS="REPLACEABLE"
><I
>from_json</I
></TT
>
with all object fields that have null values omitted. Other null values
are untouched.
</TD
><TD
><TT
CLASS="LITERAL"
>json_strip_nulls('[{"f1":1,"f2":null},2,null,3]')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>[{"f1":1},2,null,3]</TT
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>jsonb_set(target jsonb, path text[], new_value jsonb [<SPAN
CLASS="OPTIONAL"
>, create_missing boolean</SPAN
>])</TT
>
</P
></TD
><TD
><P
><TT
CLASS="TYPE"
>jsonb</TT
></P
></TD
><TD
> Returns <TT
CLASS="REPLACEABLE"
><I
>target</I
></TT
>
with the section designated by <TT
CLASS="REPLACEABLE"
><I
>path</I
></TT
>
replaced by <TT
CLASS="REPLACEABLE"
><I
>new_value</I
></TT
>, or with
<TT
CLASS="REPLACEABLE"
><I
>new_value</I
></TT
> added if
<TT
CLASS="REPLACEABLE"
><I
>create_missing</I
></TT
> is true (default is
<TT
CLASS="LITERAL"
>true</TT
>) and the item
designated by <TT
CLASS="REPLACEABLE"
><I
>path</I
></TT
> does not exist.
As with the path oriented operators, negative integers that
appear in <TT
CLASS="REPLACEABLE"
><I
>path</I
></TT
> count from the end
of JSON arrays.
</TD
><TD
><P
><TT
CLASS="LITERAL"
>jsonb_set('[{"f1":1,"f2":null},2,null,3]', '{0,f1}','[2,3,4]', false)</TT
>
</P
><P
><TT
CLASS="LITERAL"
>jsonb_set('[{"f1":1,"f2":null},2]', '{0,f3}','[2,3,4]')</TT
>
</P
></TD
><TD
><P
><TT
CLASS="LITERAL"
>[{"f1":[2,3,4],"f2":null},2,null,3]</TT
>
</P
><P
><TT
CLASS="LITERAL"
>[{"f1": 1, "f2": null, "f3": [2, 3, 4]}, 2]</TT
>
</P
></TD
></TR
><TR
><TD
> <P
><TT
CLASS="LITERAL"
> jsonb_insert(target jsonb, path text[], new_value jsonb [<SPAN
CLASS="OPTIONAL"
>, insert_after boolean</SPAN
>])
</TT
></P
>
</TD
><TD
><P
><TT
CLASS="TYPE"
>jsonb</TT
></P
></TD
><TD
> Returns <TT
CLASS="REPLACEABLE"
><I
>target</I
></TT
> with
<TT
CLASS="REPLACEABLE"
><I
>new_value</I
></TT
> inserted. If
<TT
CLASS="REPLACEABLE"
><I
>target</I
></TT
> section designated by
<TT
CLASS="REPLACEABLE"
><I
>path</I
></TT
> is in a JSONB array,
<TT
CLASS="REPLACEABLE"
><I
>new_value</I
></TT
> will be inserted before target or
after if <TT
CLASS="REPLACEABLE"
><I
>insert_after</I
></TT
> is true (default is
<TT
CLASS="LITERAL"
>false</TT
>). If <TT
CLASS="REPLACEABLE"
><I
>target</I
></TT
> section
designated by <TT
CLASS="REPLACEABLE"
><I
>path</I
></TT
> is in JSONB object,
<TT
CLASS="REPLACEABLE"
><I
>new_value</I
></TT
> will be inserted only if
<TT
CLASS="REPLACEABLE"
><I
>target</I
></TT
> does not exist. As with the path
oriented operators, negative integers that appear in
<TT
CLASS="REPLACEABLE"
><I
>path</I
></TT
> count from the end of JSON arrays.
</TD
><TD
> <P
><TT
CLASS="LITERAL"
> jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"')
</TT
></P
>
<P
><TT
CLASS="LITERAL"
> jsonb_insert('{"a": [0,1,2]}', '{a, 1}', '"new_value"', true)
</TT
></P
>
</TD
><TD
><P
><TT
CLASS="LITERAL"
>{"a": [0, "new_value", 1, 2]}</TT
>
</P
><P
><TT
CLASS="LITERAL"
>{"a": [0, 1, "new_value", 2]}</TT
>
</P
></TD
></TR
><TR
><TD
><P
><TT
CLASS="LITERAL"
>jsonb_pretty(from_json jsonb)</TT
>
</P
></TD
><TD
><P
><TT
CLASS="TYPE"
>text</TT
></P
></TD
><TD
> Returns <TT
CLASS="REPLACEABLE"
><I
>from_json</I
></TT
>
as indented JSON text.
</TD
><TD
><TT
CLASS="LITERAL"
>jsonb_pretty('[{"f1":1,"f2":null},2,null,3]')</TT
></TD
><TD
><PRE
CLASS="PROGRAMLISTING"
>[
{
"f1": 1,
"f2": null
},
2,
null,
3
]</PRE
>
</TD
></TR
></TBODY
></TABLE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> Many of these functions and operators will convert Unicode escapes in
JSON strings to the appropriate single character. This is a non-issue
if the input is type <TT
CLASS="TYPE"
>jsonb</TT
>, because the conversion was already
done; but for <TT
CLASS="TYPE"
>json</TT
> input, this may result in throwing an error,
as noted in <A
HREF="datatype-json.html"
>Section 8.14</A
>.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> While the examples for the functions
<CODE
CLASS="FUNCTION"
>json_populate_record</CODE
>,
<CODE
CLASS="FUNCTION"
>json_populate_recordset</CODE
>,
<CODE
CLASS="FUNCTION"
>json_to_record</CODE
> and
<CODE
CLASS="FUNCTION"
>json_to_recordset</CODE
> use constants, the typical use
would be to reference a table in the <TT
CLASS="LITERAL"
>FROM</TT
> clause
and use one of its <TT
CLASS="TYPE"
>json</TT
> or <TT
CLASS="TYPE"
>jsonb</TT
> columns
as an argument to the function. Extracted key values can then be
referenced in other parts of the query, like <TT
CLASS="LITERAL"
>WHERE</TT
>
clauses and target lists. Extracting multiple values in this
way can improve performance over extracting them separately with
per-key operators.
</P
><P
> JSON keys are matched to identical column names in the target
row type. JSON type coercion for these functions is <SPAN
CLASS="QUOTE"
>"best
effort"</SPAN
> and may not result in desired values for some types.
JSON fields that do not appear in the target row type will be
omitted from the output, and target columns that do not match any
JSON field will simply be NULL.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> All the items of the <TT
CLASS="LITERAL"
>path</TT
> parameter of <TT
CLASS="LITERAL"
>jsonb_set</TT
>
as well as <TT
CLASS="LITERAL"
>jsonb_insert</TT
> except the last item must be present
in the <TT
CLASS="LITERAL"
>target</TT
>. If <TT
CLASS="LITERAL"
>create_missing</TT
> is false, all
items of the <TT
CLASS="LITERAL"
>path</TT
> parameter of <TT
CLASS="LITERAL"
>jsonb_set</TT
> must be
present. If these conditions are not met the <TT
CLASS="LITERAL"
>target</TT
> is
returned unchanged.
</P
><P
> If the last path item is an object key, it will be created if it
is absent and given the new value. If the last path item is an array
index, if it is positive the item to set is found by counting from
the left, and if negative by counting from the right - <TT
CLASS="LITERAL"
>-1</TT
>
designates the rightmost element, and so on.
If the item is out of the range -array_length .. array_length -1,
and create_missing is true, the new value is added at the beginning
of the array if the item is negative, and at the end of the array if
it is positive.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> The <TT
CLASS="LITERAL"
>json_typeof</TT
> function's <TT
CLASS="LITERAL"
>null</TT
> return value
should not be confused with a SQL NULL. While
calling <TT
CLASS="LITERAL"
>json_typeof('null'::json)</TT
> will
return <TT
CLASS="LITERAL"
>null</TT
>, calling <TT
CLASS="LITERAL"
>json_typeof(NULL::json)</TT
>
will return a SQL NULL.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> If the argument to <TT
CLASS="LITERAL"
>json_strip_nulls</TT
> contains duplicate
field names in any object, the result could be semantically somewhat
different, depending on the order in which they occur. This is not an
issue for <TT
CLASS="LITERAL"
>jsonb_strip_nulls</TT
> since <TT
CLASS="TYPE"
>jsonb</TT
> values never have
duplicate object field names.
</P
></BLOCKQUOTE
></DIV
><P
> See also <A
HREF="functions-aggregate.html"
>Section 9.20</A
> for the aggregate
function <CODE
CLASS="FUNCTION"
>json_agg</CODE
> which aggregates record
values as JSON, and the aggregate function
<CODE
CLASS="FUNCTION"
>json_object_agg</CODE
> which aggregates pairs of values
into a JSON object, and their <TT
CLASS="TYPE"
>jsonb</TT
> equivalents,
<CODE
CLASS="FUNCTION"
>jsonb_agg</CODE
> and <CODE
CLASS="FUNCTION"
>jsonb_object_agg</CODE
>.
</P
></DIV
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