查找表或视图的依赖对象

背景

在 PostgreSQL 中删除（或替换）对象时，如果存在依赖关系，则删除将失败（不指定CASCADE).

Problem

数据库返回的错误信息没有列出依赖对象。

示例解决方案

该查询可能类似于：

SELECT * FROM information_schema i, pg_depend pd WHERE
  i.object_id = pd.object_id AND
  i.object_type = 'TABLE' AND
  i.object_schema = 'public' AND
  i.object_name = 'table_with_dependents';

The objid不见了。

Related

• http://postgresql.1045698.n5.nabble.com/information-schema-problem-td2144069.html http://postgresql.1045698.n5.nabble.com/information-schema-problem-td2144069.html
• http://www.alberton.info/postgresql_meta_info.html http://www.alberton.info/postgresql_meta_info.html

Question

如何按名称和类型生成依赖对象的列表？

建议的解决方案对我的 postgresql 9.1.4 不起作用

这有效：

SELECT dependent_ns.nspname as dependent_schema
, dependent_view.relname as dependent_view 
, source_ns.nspname as source_schema
, source_table.relname as source_table
, pg_attribute.attname as column_name
FROM pg_depend 
JOIN pg_rewrite ON pg_depend.objid = pg_rewrite.oid 
JOIN pg_class as dependent_view ON pg_rewrite.ev_class = dependent_view.oid 
JOIN pg_class as source_table ON pg_depend.refobjid = source_table.oid 
JOIN pg_attribute ON pg_depend.refobjid = pg_attribute.attrelid 
    AND pg_depend.refobjsubid = pg_attribute.attnum 
JOIN pg_namespace dependent_ns ON dependent_ns.oid = dependent_view.relnamespace
JOIN pg_namespace source_ns ON source_ns.oid = source_table.relnamespace
WHERE 
source_ns.nspname = 'my_schema'
AND source_table.relname = 'my_table'
AND pg_attribute.attnum > 0 
AND pg_attribute.attname = 'my_column'
ORDER BY 1,2;