PostgreSQL 中物化视图的列名和数据类型？

Question

对于一般表和视图，我可以通过运行以下查询来查看它们的数据类型：

select data_type from information_schema.columns
where .....

然而，这里似乎没有任何关于物化视图的信息。

我可以通过运行获得物化视图的列列表：

    SELECT
      a.attname as column_name
  FROM
      pg_catalog.pg_attribute a
      INNER JOIN
       (SELECT c.oid,
          n.nspname,
          c.relname
        FROM pg_catalog.pg_class c
             LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
        WHERE c.relname ~ ('^(materializedview)$')
          AND pg_catalog.pg_table_is_visible(c.oid)
        ORDER BY 2, 3) b
      ON a.attrelid = b.oid
      INNER JOIN
       (SELECT
            a.attrelid,
            max(a.attnum) as max_attnum
        FROM pg_catalog.pg_attribute a
        WHERE a.attnum > 0
          AND NOT a.attisdropped
        GROUP BY a.attrelid) e
      ON a.attrelid=e.attrelid
  WHERE a.attnum > 0
    AND NOT a.attisdropped
  ORDER BY a.attnum

但是，我无法弄清楚我是否可以确定基础列/数据类型是什么。

有没有办法查看这些信息？

Answer 1

我认为你非常接近。最后一步是加入pg_type：

join pg_catalog.pg_type as tp on tp.oid = attr.atttypid

tp.typname 字段将具有数据类型。

以下查询使用命名空间（例如模式）和关系（例如物化视图）名称获取列数据类型：

select 
    attr.attnum,
    ns.nspname as schema_name, 
    cls.relname as table_name, 
    attr.attname as column_name,
    tp.typname as datatype
from pg_catalog.pg_attribute as attr
join pg_catalog.pg_class as cls on cls.oid = attr.attrelid
join pg_catalog.pg_namespace as ns on ns.oid = cls.relnamespace
join pg_catalog.pg_type as tp on tp.oid = attr.atttypid
where 
    ns.nspname = 'your_schema'
    and cls.relname = 'your_materialized_view'
    and attr.attnum >= 1
order by 
    attr.attnum

你必须改变'your_schema'和'your_materialized_view'。