这篇文章主要介绍“PostgreSQL的OID类型是什么”，在日常操作中，相信很多人在PostgreSQL的OID类型是什么问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”PostgreSQL的OID类型是什么”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
OID定义为无符号整型数字,PG内置了转换函数从regproc, regprocedure, regoper, regoperator, regclass, regtype, regrole, regnamespace, regconfig, and regdictionary这些类型转换为OID.
TODO
下面是一些例子:
查询某张表的属性
[local]:5432 pg12@testdb=# SELECT * FROM pg_attribute WHERE attrelid = (SELECT oid FROM pg_class WHERE relname = 'tbl') limit 1; -[ RECORD 1 ]-+--------- attrelid | 32774 attname | tableoid atttypid | 26 attstattarget | 0 attlen | 4 attnum | -6 attndims | 0 attcacheoff | -1 atttypmod | -1 attbyval | t attstorage | p attalign | i attnotnull | t atthasdef | f atthasmissing | f attidentity | attgenerated | attisdropped | f attislocal | t attinhcount | 0 attcollation | 0 attacl | attoptions | attfdwoptions | attmissingval | Time: 5.209 ms --> [local]:5432 pg12@testdb=# SELECT * FROM pg_attribute where attrelid = 'tbl'::regclass limit 1; -[ RECORD 1 ]-+--------- attrelid | 32774 attname | tableoid atttypid | 26 attstattarget | 0 attlen | 4 attnum | -6 attndims | 0 attcacheoff | -1 atttypmod | -1 attbyval | t attstorage | p attalign | i attnotnull | t atthasdef | f atthasmissing | f attidentity | attgenerated | attisdropped | f attislocal | t attinhcount | 0 attcollation | 0 attacl | attoptions | attfdwoptions | attmissingval | Time: 1.205 ms
查询操作符+的相关信息
[local]:5432 pg12@testdb=# select * from pg_operator where oid='+(int,float)'::regoperator; ERROR: operator does not exist: +(int,float) LINE 1: select * from pg_operator where oid='+(int,float)'::regopera... ^ Time: 1.502 ms [local]:5432 pg12@testdb=# select * from pg_operator where oid='+(float,float)'::regoperator; -[ RECORD 1 ]+--------- oid | 591 oprname | + oprnamespace | 11 oprowner | 10 oprkind | b oprcanmerge | f oprcanhash | f oprleft | 701 oprright | 701 oprresult | 701 oprcom | 591 oprnegate | 0 oprcode | float8pl oprrest | - oprjoin | - Time: 3.446 ms
注意:操作符需指定参数.
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