Map ClickHouse JSON type to PostgreSQL JSONB

Add support for JSONB to `INSERT` statements and, when importing tables,
map the ClickHouse JSON type to PostgreSQL JSONB. This increases the
what users can do with these values; they can still use JSON for
manually-created tables.

Does not yet include binary engine support for JSON, which will requires
support from clickhouse-cpp (ClickHouse/clickhouse-cpp#450).

Author: theory

doc/pg_clickhouse.md

@@ -310,7 +310,7 @@ types:
  Int32      | integer          | 
  Int64      | bigint           | 
  Int8       | smallint         | 
- JSON       | json             | HTTP engine only
+ JSON       | jsonb            | HTTP engine only
  String     | text             | 
  UInt16     | integer          | 
  UInt32     | bigint           | 

src/pglink.c

@@ -400,6 +400,7 @@ extend_insert_query(ch_http_insert_state * state, TupleTableSlot * slot)
 				case VARCHAROID:
 				case TEXTOID:
 				case JSONOID:
+				case JSONBOID:
 				case NAMEOID:
 				case BITOID:
 				case BYTEAOID:
@@ -785,7 +786,7 @@ binary_insert_tuple(void *istate, TupleTableSlot * slot)
 		('UUID',     'uuid',             ''),
 		('IPv4',     'inet',             ''),
 		('IPv6',     'inet',             ''),
-		('JSON',     'json',             'HTTP engine only')
+		('JSON',     'jsonb',            'HTTP engine only')
 	) AS v("ClickHouse", "PostgreSQL", "Notes")
 	ORDER BY "ClickHouse";
 
@@ -810,7 +811,7 @@ static char *str_types_map[][2] = {
 	{"UUID", "UUID"},
 	{"IPv4", "inet"},
 	{"IPv6", "inet"},
-	{"JSON", "JSON"},
+	{"JSON", "JSONB"},
 	{NULL, NULL},
 };
 

test/expected/json.out

@@ -34,7 +34,7 @@ IMPORT FOREIGN SCHEMA "json_test" FROM SERVER binary_json_loopback INTO json_bin
  Column |  Type   | Collation | Nullable | Default | FDW options 
 --------+---------+-----------+----------+---------+-------------
  id     | integer |           | not null |         | 
- data   | json    |           | not null |         | 
+ data   | jsonb   |           | not null |         | 
 Server: binary_json_loopback
 FDW options: (database 'json_test', table_name 'things', engine 'MergeTree')
 
@@ -44,7 +44,7 @@ IMPORT FOREIGN SCHEMA "json_test" FROM SERVER http_json_loopback INTO json_http;
  Column |  Type   | Collation | Nullable | Default | FDW options 
 --------+---------+-----------+----------+---------+-------------
  id     | integer |           | not null |         | 
- data   | json    |           | not null |         | 
+ data   | jsonb   |           | not null |         | 
 Server: http_json_loopback
 FDW options: (database 'json_test', table_name 'things', engine 'MergeTree')
 
@@ -64,12 +64,12 @@ SELECT * FROM json_bin.things ORDER BY id;
 ERROR:  pg_clickhouse: unsupported column type: JSON
 DETAIL:  Remote Query: SELECT id, data FROM json_test.things ORDER BY id ASC NULLS LAST
 SELECT * FROM json_http.things ORDER BY id;
- id |                           data                           
-----+----------------------------------------------------------
-  1 | {"id":1,"name":"widget","size":"large","stocked":true}
-  2 | {"id":2,"name":"sprocket","size":"small","stocked":true}
-  3 | {"id":3,"name":"gizmo","size":"medium","stocked":true}
-  4 | {"id":4,"name":"doodad","size":"large","stocked":false}
+ id |                              data                               
+----+-----------------------------------------------------------------
+  1 | {"id": 1, "name": "widget", "size": "large", "stocked": true}
+  2 | {"id": 2, "name": "sprocket", "size": "small", "stocked": true}
+  3 | {"id": 3, "name": "gizmo", "size": "medium", "stocked": true}
+  4 | {"id": 4, "name": "doodad", "size": "large", "stocked": false}
 (4 rows)
 
 SELECT clickhouse_raw_query('DROP DATABASE json_test');

test/expected/json_1.out

@@ -34,7 +34,7 @@ IMPORT FOREIGN SCHEMA "json_test" FROM SERVER binary_json_loopback INTO json_bin
  Column |  Type   | Collation | Nullable | Default | FDW options 
 --------+---------+-----------+----------+---------+-------------
  id     | integer |           | not null |         | 
- data   | json    |           | not null |         | 
+ data   | jsonb   |           | not null |         | 
 Server: binary_json_loopback
 FDW options: (database 'json_test', table_name 'things', engine 'MergeTree')
 
@@ -44,7 +44,7 @@ IMPORT FOREIGN SCHEMA "json_test" FROM SERVER http_json_loopback INTO json_http;
  Column |  Type   | Collation | Nullable | Default | FDW options 
 --------+---------+-----------+----------+---------+-------------
  id     | integer |           | not null |         | 
- data   | json    |           | not null |         | 
+ data   | jsonb   |           | not null |         | 
 Server: http_json_loopback
 FDW options: (database 'json_test', table_name 'things', engine 'MergeTree')
 
@@ -64,12 +64,12 @@ SELECT * FROM json_bin.things ORDER BY id;
 ERROR:  pg_clickhouse: unsupported column type: JSON
 DETAIL:  Remote Query: SELECT id, data FROM json_test.things ORDER BY id ASC NULLS LAST
 SELECT * FROM json_http.things ORDER BY id;
- id |                            data                            
-----+------------------------------------------------------------
-  1 | {"id":"1","name":"widget","size":"large","stocked":true}
-  2 | {"id":"2","name":"sprocket","size":"small","stocked":true}
-  3 | {"id":"3","name":"gizmo","size":"medium","stocked":true}
-  4 | {"id":"4","name":"doodad","size":"large","stocked":false}
+ id |                               data                                
+----+-------------------------------------------------------------------
+  1 | {"id": "1", "name": "widget", "size": "large", "stocked": true}
+  2 | {"id": "2", "name": "sprocket", "size": "small", "stocked": true}
+  3 | {"id": "3", "name": "gizmo", "size": "medium", "stocked": true}
+  4 | {"id": "4", "name": "doodad", "size": "large", "stocked": false}
 (4 rows)
 
 SELECT clickhouse_raw_query('DROP DATABASE json_test');