Postgres: How to convert a json string to text?

Question

Json value may consist of a string value. eg.:

postgres=# SELECT to_json(\'Some \"text\"\'::TEXT);
     to_json
-----------------
 \"Some \\\"text\\\"\"
         


        

Answer 1

There is no way in PostgreSQL to deconstruct a scalar JSON object. Thus, as you point out,

select  length(to_json('Some "text"'::TEXT) ::TEXT);

is 15,

The trick is to convert the JSON into an array of one JSON element, then extract that element using ->>.

select length( array_to_json(array[to_json('Some "text"'::TEXT)])->>0 );

will return 11.