SqlKoram - 加入子选择但如何指定别名？

Question

我想在此查询中为子选择分配别名：

(->
  (korma/select* table_a)
  (korma/join
      (korma/subselect table_b
                       (korma/fields :id (korma/raw "COUNT(*) AS count"))
                       (korma/group :id)
   (= :id :id))

这是我想要创建的SQL：

SELECT * FROM table_a LEFT JOIN (SELECT id, COUNT(*) AS count FROM table_b GROUP BY id) AS b b.id = id;

但是目前sql korma刚刚生成：

SELECT * FROM table_a LEFT JOIN (SELECT id, COUNT(*) AS count FROM table_b GROUP BY id) id = id;

Answer 1

我需要将子选择定义为单独的实体，见下文：

(korma/defentity sub-select
             (korma/table (korma/subselect table_b
                                           (korma/fields :id(korma/raw "COUNT(*) AS count"))
                                           (korma/group :id)) :b))

(->
  (korma/select* table_a)
  (korma/join sub-select (= :b.id :id)))

生成以下查询：

SELECT * FROM table_a LEFT JOIN (SELECT id, COUNT(*) AS count FROM table_b GROUP BY id) a.id = id;