将视图从 SQL 服务器转换为 Redshift

Question

我在 SQL 服务器中有视图，我需要将其转换为 Redshift

视图如下：

IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'dbo.BE_ContactRelationsDual') AND type in (N'V'))
    DROP VIEW public.contactrelationsdual;
GO

CREATE VIEW public.contactrelationsdual
WITH SCHEMABINDING
AS
SELECT  CASE d.id
        WHEN 0 THEN
                cr.contactId
        ELSE
                cr.relatedContactId
        END me,
        CASE d.id
        WHEN 0 THEN
                cr.relatedContactId
        ELSE
                cr.contactId
        END him,
        cr.id, 
        cr.permissionId
FROM    public.contact_relations cr
CROSS JOIN
        public.system_dual d
WHERE   cr.contactId > 0
        AND cr.relatedContactId > 0
        AND cr.deletedDate IS NULL
GO

CREATE UNIQUE CLUSTERED INDEX
        UX_BE_ContactRelationsDual_Me_Him
ON      public.contactrelationsdual (me, him)
GO

我需要将其转换为红移。我有 2 个问题：

这个：

CREATE VIEW public.contactrelationsdual
WITH SCHEMABINDING

还有这个：

IF EXISTS (SELECT * FROM sys.objects WHERE object_id =
OBJECT_ID(N'dbo.BE_ContactRelationsDual') AND type in (N'V'))     DROP
VIEW public.contactrelationsdual; GO

如何正确地将其转换为 Redshift。

Answer 1

移除with schemabinding:

CREATE VIEW public.contactrelationsdual AS
SELECT (CASE d.id WHEN 0 THEN cr.contactId ELSE cr.relatedContactId
        END) as me,
       (CASE d.id WHEN 0 THEN cr.relatedContactId ELSE cr.contactId
        END) as  him,
        cr.id, 
        cr.permissionId
FROM public.contact_relations cr CROSS JOIN
     public.system_dual d
WHERE cr.contactId > 0 AND
      cr.relatedContactId > 0 AND
      cr.deletedDate IS NULL;

这是非常标准的 SQL，应该适用于几乎任何数据库。

IF EXISTS部分可以替换为：

drop view if exists public.contactrelationsdual;

Redshift 中不需要聚簇索引。

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