PostgreSQL中物化视图的列名和数据类型? [英] Column names and data types for materialized views in PostgreSQL?
问题描述
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:
For general tables and views, I can see their data type by running the following query:
select data_type from information_schema.columns
where .....
但是,似乎没有任何有关物化的信息视图出现在这里。
However it does not seem that any information about materialized views appear here.
我能够通过运行以下命令来获取物化视图的列列表:
I am able to get a list of columns for a materialized view by running:
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
我无法弄清楚是否可以确定底层的列/数据类型是什么。
But, I have not been able to figure out if I can determine what the underlying column/data type is.
是否可以查看此信息?
推荐答案
我认为您非常亲密。最后一步是加入 pg_type
:
I think you're very close. Last step would be to join with pg_type
:
join pg_catalog.pg_type as tp on tp.typelem = a.atttypid
字段 tp.typname
将具有数据类型。尽管似乎必须添加一个过滤器才能删除 line
数据类型,但无论如何:
The field tp.typname
would have the datatype. Although it seems a filter must be added to remove line
datatypes, whatever that is:
cast(tp.typanalyze as text) = 'array_typanalyze'
我不完全了解底层数据模型,因此请在下面使用我的解决方案。无论如何,基于您的贡献,我最终得到了以下查询,该查询使用名称空间(例如,架构)和关系(例如,物化视图)名称获取列数据类型:
I don't fully understand the underlying data model, so use my solution below with a grain of salt. Anyway, based on your contribution I ended up with the following query which gets column datatypes using namespace (e.g., schema) and relation (e.g., materialized view) name:
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
您必须更改您的模式
和您的物化视图
。
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