Syntax

json_serialize

Description of the illustration json_serialize.eps

Purpose

The json_serialize function takes JSON data of any SQL data type ( VARCHAR2, CLOB, BLOB ) as input and returns a textual representation of it. You typically use it to transform the result of a query.

You can use json_serialize to convert binary JSON data to textual form (VARCHAR2 or CLOB), or to transform textual JSON data by pretty-printing it or escaping non-ASCII Unicode characters in it.

expr

expr is the input expression. Can be any one of type VARCHAR2, CLOB, or BLOB.

JSON_returning_clause

Use the JSON_returning_clause to specify the return type. The return type can be one of VARCHAR2, CLOB, or BLOB.

The default return type is VARCHAR2(4000).

If the return type is RAW or BLOB, it contains UTF8 encoded JSON text.

PRETTY

Specify PRETTY if you want the result to be formatted for human readability.

ASCII

Specify ASCII if you want non-ASCII characters to be output using JSON escape sequences.

TRUNCATE

Specify TRUNCATE, if you want the textual output in the result document to fit into the buffer of the specified return type.

JSON_on_error_clause

Specify JSON_on_error_clause to control the handling of processing errors.

ERROR ON ERROR is the default.

EMPTY ON ERROR is not supported.

If you specify TRUNCATE with JSON_on_error_clause, then a value too large for the return type will be truncated to fit into the buffer instead of raising an error.

Example

SELECT JSON_SERIALIZE ('{a:[1,2,3,4]}' RETURNING VARCHAR2(3) TRUNCATE ERROR ON ERROR) from dual
–-------
{"a