Python：读取PostgreSQL表的关系（外键表）

我需要使用python阅读postgres数据库模式。我已经可以使用

cursor.execute(
  "select relname 
  from pg_class 
  where relkind='r' and relname !~ '^(pg_|sql_)';")

以及

---

我还想阅读表之间的关系。有人知道怎么做吗？

请尝试使用此查询，它应该可以正常工作：

cursor.execute("""SELECT
    tc.constraint_name, tc.table_name, kcu.column_name, 
    ccu.table_name AS foreign_table_name,
    ccu.column_name AS foreign_column_name 
FROM 
    information_schema.table_constraints AS tc 
    JOIN information_schema.key_column_usage AS kcu
      ON tc.constraint_name = kcu.constraint_name
    JOIN information_schema.constraint_column_usage AS ccu
      ON ccu.constraint_name = tc.constraint_name
WHERE constraint_type = 'FOREIGN KEY' AND tc.table_name='+ table_name +'""")

我将从information\u schema.key\u column\u用法和information\u schema.table\u约束开始。请特别注意列约束模式和表模式。可以在多个架构中使用相同的表名。

cursor.execute("""SELECT
    tc.constraint_name, tc.table_name, kcu.column_name, 
    ccu.table_name AS foreign_table_name,
    ccu.column_name AS foreign_column_name 
FROM 
    information_schema.table_constraints AS tc 
    JOIN information_schema.key_column_usage AS kcu
      ON tc.constraint_name = kcu.constraint_name
    JOIN information_schema.constraint_column_usage AS ccu
      ON ccu.constraint_name = tc.constraint_name
WHERE constraint_type = 'FOREIGN KEY' AND tc.table_name='+ table_name +'""")