Contents
jsonb_typeof()
A function returning the type of a jsonb value as a string
jsonb_typeof() is a system function returning type of the top-level jsonb value as a text string
jsonb_typeof() was added in PostgreSQL 9.4.
Usage
json_typeof (jsonb) →text
One of the following values will be returned:
objectarraystringnumberbooleannull
Note that these values, particularly in the case of null, are not direct equivalents of the corresponding SQL data types.
Change history
- PostgreSQL 9.4
- added (commit d9134d0a)
Examples
Using jsonb_typeof() to determine the type of various jsonb values:
postgres=# SELECT jsonb_typeof('{"foo":[]}'::jsonb);
jsonb_typeof
--------------
object
(1 row)
postgres=# SELECT jsonb_typeof('[]'::jsonb);
jsonb_typeof
--------------
array
(1 row)
postgres=# SELECT jsonb_typeof('"foo"'::jsonb);
jsonb_typeof
--------------
string
(1 row)
postgres=# SELECT jsonb_typeof('123'::jsonb);
jsonb_typeof
--------------
number
(1 row)
postgres=# SELECT jsonb_typeof('false'::jsonb);
jsonb_typeof
--------------
boolean
(1 row)
postgres=# SELECT jsonb_typeof('null'::jsonb);
jsonb_typeof
--------------
null
(1 row)
Note that any numeric value maps to a number type:
postgres=# SELECT jsonb_typeof(123::int::text::jsonb); jsonb_typeof -------------- number (1 row) postgres=# SELECT jsonb_typeof(1.23::numeric::text::jsonb); jsonb_typeof ------------- number (1 row)
A jsonb null is not equivalent to an SQL NULL:
postgres=# SELECT jsonb_typeof('null'::jsonb),
jsonb_typeof(NULL::jsonb) IS NULL;
jsonb_typeof | ?column?
--------------+----------
null | t
(1 row)
References
- PostgreSQL documentation: JSON Processing Functions