如何在创建物化视图时添加具有不同值的列？

Question

我正在从几个不同的 table 创建实体化视图，但我缺少 class 值，因为它不在原点 table 中。如何在创建物化视图时添加列并设置值？我想要一个名为 class 的新列，并用它的名称为每个 SELECT 填充它，以便以后能够过滤 MV。我知道您可以将列直接添加到原点 table，但由于 table 总是被删除并从不同的人那里重新填充，我想直接在 MV 中进行。

CREATE MATERIALIZED VIEW vt_views.poi
TABLESPACE pg_default
AS
SELECT tim_bergname.name,
       tim_bergname.info1 AS hoehe,
       NULL AS art,
       NULL AS name_alternative,
       tim_bergname.info2 AS region,
       NULL AS text_hoehe,
       NULL AS name_lang,
       tim_bergname.geoloc,
       tim_bergname.symbolnummer
FROM tim_bergname

UNION ALL

SELECT tim_haus_huette.name,
       NULL,
       tim_haus_huette.info1 AS art,
       NULL,
       tim_haus_huette.info2 AS region,
       NULL,
       NULL,
       tim_haus_huette.geoloc,
       tim_haus_huette.symbolnummer
FROM tim_haus_huette

UNION ALL

... severall other SELECTS

UNION ALL

SELECT tim_wohnmobilstellplatz.name,
       NULL,
       NULL,
       NULL,
       NULL,
       NULL,
       NULL,
       tim_wohnmobilstellplatz.geoloc,
       tim_wohnmobilstellplatz.symbolnummer
FROM tim_wohnmobilstellplatz
WITH DATA;

和索引：

CREATE INDEX poi_geoloc_idx
    ON vt_views.poi USING gist (geoloc)
TABLESPACE pg_default;

Answer 1

有两种方法可以做到这一点：

使用tableoid系统栏：

SELECT tableoid::regclass::text as class,
       tim_bergname.name,
       tim_bergname.info1 AS hoehe,
       NULL AS art,
       NULL AS name_alternative,
       tim_bergname.info2 AS region,
       NULL AS text_hoehe,
       NULL AS name_lang,
       tim_bergname.geoloc,
       tim_bergname.symbolnummer
FROM tim_bergname

或者简单地添加一个常量值：

SELECT 'tim_bergname' as class,
       tim_bergname.name,
       tim_bergname.info1 AS hoehe,
       NULL AS art,
       NULL AS name_alternative,
       tim_bergname.info2 AS region,
       NULL AS text_hoehe,
       NULL AS name_lang,
       tim_bergname.geoloc,
       tim_bergname.symbolnummer
FROM tim_bergname

如何在创建物化视图时添加具有不同值的列？

How to add column with different values while CREATING MATERIALIZED VIEW?

postgresql

select

materialized-views