物化视图的列数据类型？

Question

对于常规表和视图,我可以通过运行以下查询来查看其数据类型:

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

但是,似乎没有关于物化视图的任何信息出现在此处.

通过运行,我能够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底层列/数据类型是什么.

有没有办法查看这些信息？

Answer 1

我觉得你很亲密.最后一步是加入pg_type:

join pg_catalog.pg_type as tp on tp.typelem = a.atttypid

该字段tp.typname将具有数据类型.虽然看起来必须添加一个过滤器来删除line数据类型,不管是什么:

cast(tp.typanalyze as text) = 'array_typanalyze'

我并不完全了解基础数据模型,因此请使用下面的解决方案.总之,根据你的贡献,我结束了以下查询它获取使用命名空间(例如,模式)和关系列数据类型(如物化视图)名称:

select 
    ns.nspname as schema_name, 
    cls.relname as table_name, 
    attr.attname as column_name,
    trim(leading '_' from 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.typelem = attr.atttypid
where 
    ns.nspname = 'your_schema' and
    cls.relname = 'your_materialized_view' and 
    not attr.attisdropped and 
    cast(tp.typanalyze as text) = 'array_typanalyze' and 
    attr.attnum > 0
order by 
    attr.attnum

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