diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be7b00b1f32..e397386bf24 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -10095,7 +10095,7 @@ table2-mapping </entry> <entry><type>json</type></entry> <entry> - Returns JSON object pointed to by <parameter>path_elems</parameter>. + Returns JSON value pointed to by <parameter>path_elems</parameter>. </entry> <entry><literal>json_extract_path('{"f2":{"f3":1},"f4":{"f5":99,"f6":"foo"}}','f4')</literal></entry> <entry><literal>{"f5":99,"f6":"foo"}</literal></entry> @@ -10109,7 +10109,7 @@ table2-mapping </entry> <entry><type>text</type></entry> <entry> - Returns JSON object pointed to by <parameter>path_elems</parameter>. + Returns JSON value pointed to by <parameter>path_elems</parameter>. </entry> <entry><literal>json_extract_path_text('{"f2":{"f3":1},"f4":{"f5":99,"f6":"foo"}}','f4', 'f6')</literal></entry> <entry><literal>foo</literal></entry> @@ -10192,7 +10192,7 @@ table2-mapping </entry> <entry><type>SETOF json</type></entry> <entry> - Expands a JSON array to a set of JSON elements. + Expands a JSON array to a set of JSON values. </entry> <entry><literal>json_array_elements('[1,true, [2,false]]')</literal></entry> <entry> @@ -10205,6 +10205,23 @@ table2-mapping </programlisting> </entry> </row> + <row> + <entry> + <indexterm> + <primary>json_typeof</primary> + </indexterm> + <literal>json_typeof(json)</literal> + </entry> + <entry><type>text</type></entry> + <entry> + Returns the type of the outermost JSON value as a text string. The types are + <literal>object</>, <literal>array</>, <literal>string</>, <literal>number</>, + <literal>boolean</>, and <literal>null</>. (See note below regarding the + distinction between a JSON <literal>null</> and a SQL NULL.) + </entry> + <entry><literal>json_typeof('-123.4')</literal></entry> + <entry><literal>number</literal></entry> + </row> </tbody> </tgroup> </table> @@ -10237,6 +10254,14 @@ table2-mapping </para> </note> + <note> + <para> + The <literal>json_typeof</> function's <literal>null</> return value should not be confused + with a SQL NULL. While calling <literal>json_typeof('null'::json)</> will return <literal>null</>, + calling <literal>json_typeof(NULL::json)</> will return a SQL NULL. + </para> + </note> + <para> See also <xref linkend="functions-aggregate"> about the aggregate function <function>json_agg</function> which aggregates record |