distinctJSONPathsAndTypes

Introduced in: v24.9.0 Calculates the list of distinct paths and their types stored in JSON column.

If JSON declaration contains paths with specified types, these paths will be always included in the result of distinctJSONPaths/distinctJSONPathsAndTypes functions even if input data didn’t have values for these paths.

Syntax

distinctJSONPathsAndTypes(json)

Arguments

json — JSON column. JSON

Returned value Returns the sorted map of paths and types. Map(String, Array(String)) Examples Basic usage with mixed types

Query

DROP TABLE IF EXISTS test_json;
CREATE TABLE test_json(json JSON) ENGINE = Memory;
INSERT INTO test_json VALUES ('{"a" : 42, "b" : "Hello"}'), ('{"b" : [1, 2, 3], "c" : {"d" : {"e" : "2020-01-01"}}}'), ('{"a" : 43, "c" : {"d" : {"f" : [{"g" : 42}]}}}');

SELECT distinctJSONPathsAndTypes(json) FROM test_json;

Response

┌─distinctJSONPathsAndTypes(json)───────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ {'a':['Int64'],'b':['Array(Nullable(Int64))','String'],'c.d.e':['Date'],'c.d.f':['Array(JSON(max_dynamic_types=16, max_dynamic_paths=256))']} │
└───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

With declared JSON paths

Query

DROP TABLE IF EXISTS test_json;
CREATE TABLE test_json(json JSON(a UInt32)) ENGINE = Memory;
INSERT INTO test_json VALUES ('{"b" : "Hello"}'), ('{"b" : "World", "c" : [1, 2, 3]}');

SELECT distinctJSONPathsAndTypes(json) FROM test_json;

Response

┌─distinctJSONPathsAndTypes(json)────────────────────────────────┐
│ {'a':['UInt32'],'b':['String'],'c':['Array(Nullable(Int64))']} │
└────────────────────────────────────────────────────────────────┘

​distinctJSONPathsAndTypes

distinctJSONPathsAndTypes