postgre如何查看一个用户所有权限

在 PostgreSQL 中，可以使用以下 SQL 语句查看一个用户的所有权限：

SELECT
  nspname AS schema_name,
  relname AS object_name,
  CASE
    WHEN relkind = 'r' THEN 'table'
    WHEN relkind = 'v' THEN 'view'
    WHEN relkind = 'S' THEN 'sequence'
    WHEN relkind = 'm' THEN 'materialized view'
    WHEN relkind = 'f' THEN 'foreign table'
  END AS object_type,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'SELECT') AS select_privilege,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'INSERT') AS insert_privilege,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'UPDATE') AS update_privilege,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'DELETE') AS delete_privilege,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'TRUNCATE') AS truncate_privilege,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'REFERENCES') AS references_privilege,
  HAS_TABLE_PRIVILEGE(usename, nspname || '.' || relname, 'TRIGGER') AS trigger_privilege
FROM pg_class
JOIN pg_namespace ON pg_class.relnamespace = pg_namespace.oid
JOIN pg_user ON pg_user.usesysid = pg_class.relowner
WHERE pg_user.usename = 'username';

其中，`username` 是您要查询权限的 PostgreSQL 用户名。

该 SQL 语句将返回该用户在所有表、视图、序列等对象上的 SELECT、INSERT、UPDATE、DELETE、TRUNCATE、REFERENCES 和 TRIGGER 权限。如果该用户没有某种权限，则对应的列的值将为 `false`。如果该用户拥有某种权限，则对应的列的值将为 `true`。