Join 테이블 엔진

CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
(
    name1 [type1] [DEFAULT|MATERIALIZED|ALIAS expr1],
    name2 [type2] [DEFAULT|MATERIALIZED|ALIAS expr2],
) ENGINE = Join(join_strictness, join_type, k1[, k2, ...])

CREATE TABLE id_val(`id` UInt32, `val` UInt32) ENGINE = TinyLog;

INSERT INTO id_val VALUES (1,11), (2,12), (3,13);

CREATE TABLE id_val_join(`id` UInt32, `val` UInt8) ENGINE = Join(ANY, LEFT, id);

INSERT INTO id_val_join VALUES (1,21), (1,22), (3,23);

SELECT * FROM id_val ANY LEFT JOIN id_val_join USING (id);

┌─id─┬─val─┬─id_val_join.val─┐
│  1 │  11 │              21 │
│  2 │  12 │               0 │
│  3 │  13 │              23 │
└────┴─────┴─────────────────┘

SELECT joinGet('id_val_join', 'val', toUInt32(1));

┌─joinGet('id_val_join', 'val', toUInt32(1))─┐
│                                         21 │
└────────────────────────────────────────────┘

ALTER TABLE id_val_join DELETE WHERE id = 3;

┌─id─┬─val─┐
│  1 │  21 │
└────┴─────┘