选择语句以检索ID的代码

Question

我在表id_org中有3列（code_org，id_root_org，org）。 id_root_org指定表中某个组织的最高组织。

org 1 (id_org=1, id_root_org = 1 since it is its own root)
  --org 2 (id_org=2, id_root_org = 1)
  --org 3 (id_org=3, id_root_org = 1)
    --org 3.1 (id_org=3.1, id_root_org = 1)

如何检索所有根组织的代码？

Answer 1

看来，根是id_root_org = id_org所在的记录。要获得该行的code_org，您可以使用简单的SELECT。

SELECT code_org
       FROM elbat
       WHERE id_root_org = id_org;

Answer 2

您只想要ID_ROOT_ORG的列表？

SELECT DISTINCT ID_ROOT_ORG
FROM [TABLE_NAME]