<sect5>

<title>Examples</title>

<para>

ConstructaJSON the provided strings:

Construct JSON using the provided strings:

</para>

<screen>

SELECT JSON('{ "a" : 123, "b": [ true, "foo" ], "a" : "bar" }');

<acronym>JSON</acronym> value.

For null input, <acronym>SQL</acronym> null

(not a <acronym>JSON</acronym> null) value is returned.

For any scalar other than a number or a Boolean the text

For any scalar other than a number or a Boolean, the text

representation will be used, with escaping as necessary to make

it a valid <acronym>JSON</acronym> string value.

For details, see

<sect5>

<title>Examples</title>

<para>

ConstructaJSON from the provided values various types:

Construct JSONscalarsfrom the provided values of various types:

</para>

<screen>

SELECT JSON_SCALAR(123.45);

<para>

The <function>JSON_OBJECTAGG</function> function aggregates the provided data

into a <acronym>JSON</acronym> object. You can use this function to combine values

stored in different table columns into pairs. If you specify a <command>GROUP BY</command>

or an <command>ORDER BY</command> clause, this function returns a separate JSON object

for each table row.

stored in different table columns into pairs.

</para>

</sect5>

<title>Description</title>

<para>

<function>JSON_EXISTS</function> function checks whether the provided

The<function>JSON_EXISTS</function> function checks whether the provided

<acronym>JSON</acronym> path expression can return any <acronym>SQL/JSON</acronym> items.

</para>

</sect5>

<title>Description</title>

<para>

<function>JSON_VALUE</function> function extracts a value from the provided

The<function>JSON_VALUE</function> function extracts a value from the provided

<acronym>JSON</acronym> data and converts it to an <acronym>SQL</acronym> scalar.

If the specified JSON path expression returns more than one

<acronym>SQL/JSON</acronym> item, an error occurs. To extract

<title>Description</title>

<para>

<function>JSON_QUERY</function> function extracts an <acronym>SQL/JSON</acronym>

The<function>JSON_QUERY</function> function extracts an <acronym>SQL/JSON</acronym>

array or object from <acronym>JSON</acronym> data. This function must return

a JSON string, so if the path expression returns a scalar or multiple SQL/JSON

items, you must wrap the result using the <literal>WITH WRAPPER</literal> clause.

<title>Description</title>

<para>

<function>JSON_TABLE</function> function queries <acronym>JSON</acronym> data

The<function>JSON_TABLE</function> function queries <acronym>JSON</acronym> data

and presents the results as a relational view, which can be accessed as a

regular SQL table. You can only use <function>JSON_TABLE</function> inside the

<literal>FROM</literal> clause of the <literal>SELECT</literal> statement

<para>

The optional <replaceable>json_path_name</replaceable> serves as an

identifier of the provided <replaceable>json_path_specification</replaceable>.

The path name must be unique andcannot coincide with column names.

The path name must be unique anddistinct from the column names.

When using the <literal>PLAN</literal> clause, you must specify the names

for all the paths, including the row pattern. Each path name can appear in

the <literal>PLAN</literal> clause only once.

<title>Description</title>

<para>

<function>JSON_SERIALIZE</function> function transforms a SQL/JSON value

The<function>JSON_SERIALIZE</function> function transforms a SQL/JSON value

into a character or binary string.

</para>

</sect5>

<sect5>

<title>Examples</title>

<para>

Constructa JSON the provided strings:

Constructserialized JSON using the provided strings:

</para>

<screen>

SELECT JSON_SERIALIZE(JSON_SCALAR('foo'));

supports the following types: <type>json</type>, <type>jsonb</type>,

<type>bytea</type>, and character string types (<type>text</type>, <type>char</type>,

<type>varchar</type>, and <type>nchar</type>).

To useother types, you must createthe <literal>CAST</literal> from <type>json</type>for this type.

To useanother type, you must createa cast from <type>json</type>to that type.

By default, the <type>json</type> type is returned.

</para>

<para>

Collects all the key/value pairs into a JSON object. Key arguments

are coerced to text; value arguments are converted as per

<function>to_json</function> or <function>to_jsonb</function>

Values can be null, butnotkeys.

Values can be null, but keys cannot.

</para></entry>

<entry>No</entry>

</row>

Collects all the key/value pairs into a JSON object. Key arguments

are coerced to text; value arguments are converted as per

<function>to_json</function> or <function>to_jsonb</function>.

Values can be null, butnotkeys.

Values can be null, but keys cannot.

If there is a duplicate key an error is thrown.

</para></entry>

<entry>No</entry>