PG_AGGREGATE PG_AM PG_AMOP PG_AMPROC PG_APP_WORKLOADGROUP_MAPPING PG_ATTRDEF PG_ATTRIBUTE PG_AUTHID PG_AUTH_HISTORY PG_AUTH_MEMBERS PG_CAST PG_CLASS PG_COLLATION PG_CONSTRAINT PG_CONVERSION PG_DATABASE PG_DB_ROLE_SETTING PG_DEFAULT_ACL PG_DEPEND PG_DESCRIPTION PG_DIRECTORY PG_ENUM PG_...
OID列是隐藏属性(https://www.postgresql.org/docs/10/static/catalog-pg-database.html), select * from pg_database是查不出来的,必须select oid from pg_database 这么明确的指定oid 关于OID的更多知识,请参考 《PostgreSQL数据库内核分析》一书第15页。