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Documentation
/ Data Import
/ JSON Files
JSON Type
DuckDB supports json
via the JSON
logical type.
The JSON
logical type is interpreted as JSON, i.e., parsed, in JSON functions rather than interpreted as VARCHAR
, i.e., a regular string (modulo the equality-comparison caveat at the bottom of this page).
All JSON creation functions return values of this type.
We also allow any of DuckDB's types to be casted to JSON, and JSON to be casted back to any of DuckDB's types, for example, to cast JSON
to DuckDB's STRUCT
type, run:
SELECT '{"duck": 42}'::JSON::STRUCT(duck INTEGER);
{'duck': 42}
And back:
SELECT {duck: 42}::JSON;
{"duck":42}
This works for our nested types as shown in the example, but also for non-nested types:
SELECT '2023-05-12'::DATE::JSON;
"2023-05-12"
The only exception to this behavior is the cast from VARCHAR
to JSON
, which does not alter the data, but instead parses and validates the contents of the VARCHAR
as JSON.