目录

pg_attrdef

用于存储列默认值的系统表

pg_attrdef 是一个用于存储列默认值的系统目录表。

pg_attrdef 添加于PostgreSQL 6.2。

备注

"列 d.adsrc 不存在"

如果您遇到类似这样的错误

ERROR: column d.adsrc does not exist

这意味着您正在使用尚未更新以支持PostgreSQL 12的客户端软件。

除了升级受影响的客户端软件之外，没有其他方法可以解决此问题。

按 PostgreSQL 版本定义

pg_attrdef (PostgreSQL 17)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 oid     | oid          |           | not null | 
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree | C         | not null | 
Indexes:
    "pg_attrdef_oid_index" PRIMARY KEY, btree (oid)
    "pg_attrdef_adrelid_adnum_index" UNIQUE CONSTRAINT, btree (adrelid, adnum)

文档: pg_attrdef

pg_attrdef (PostgreSQL 16)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 oid     | oid          |           | not null | 
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree | C         | not null | 
Indexes:
    "pg_attrdef_oid_index" PRIMARY KEY, btree (oid)
    "pg_attrdef_adrelid_adnum_index" UNIQUE CONSTRAINT, btree (adrelid, adnum)

文档: pg_attrdef

pg_attrdef (PostgreSQL 15)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 oid     | oid          |           | not null | 
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree | C         | not null | 
Indexes:
    "pg_attrdef_oid_index" PRIMARY KEY, btree (oid)
    "pg_attrdef_adrelid_adnum_index" UNIQUE CONSTRAINT, btree (adrelid, adnum)

文档: pg_attrdef

pg_attrdef (PostgreSQL 14)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 oid     | oid          |           | not null | 
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree | C         | not null | 
Indexes:
    "pg_attrdef_oid_index" PRIMARY KEY, btree (oid)
    "pg_attrdef_adrelid_adnum_index" UNIQUE CONSTRAINT, btree (adrelid, adnum)

文档: pg_attrdef

pg_attrdef (PostgreSQL 13)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 oid     | oid          |           | not null | 
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree | C         | not null | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 12)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 oid     | oid          |           | not null | 
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree | C         | not null | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 11)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree |           |          | 
 adsrc   | text         |           |          | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 10)

              Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Collation | Nullable | Default 
---------+--------------+-----------+----------+---------
 adrelid | oid          |           | not null | 
 adnum   | smallint     |           | not null | 
 adbin   | pg_node_tree |           |          | 
 adsrc   | text         |           |          | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.6)

   Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Modifiers 
---------+--------------+-----------
 adrelid | oid          | not null
 adnum   | smallint     | not null
 adbin   | pg_node_tree | 
 adsrc   | text         | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.5)

   Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Modifiers 
---------+--------------+-----------
 adrelid | oid          | not null
 adnum   | smallint     | not null
 adbin   | pg_node_tree | 
 adsrc   | text         | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.4)

   Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Modifiers 
---------+--------------+-----------
 adrelid | oid          | not null
 adnum   | smallint     | not null
 adbin   | pg_node_tree | 
 adsrc   | text         | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.3)

   Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Modifiers 
---------+--------------+-----------
 adrelid | oid          | not null
 adnum   | smallint     | not null
 adbin   | pg_node_tree | 
 adsrc   | text         | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.2)

   Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Modifiers 
---------+--------------+-----------
 adrelid | oid          | not null
 adnum   | smallint     | not null
 adbin   | pg_node_tree | 
 adsrc   | text         | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.1)

   Table "pg_catalog.pg_attrdef"
 Column  |     Type     | Modifiers 
---------+--------------+-----------
 adrelid | oid          | not null
 adnum   | smallint     | not null
 adbin   | pg_node_tree | 
 adsrc   | text         | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 9.0)

 Table "pg_catalog.pg_attrdef"
 Column  |   Type   | Modifiers 
---------+----------+-----------
 adrelid | oid      | not null
 adnum   | smallint | not null
 adbin   | text     | 
 adsrc   | text     | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 8.4)

 Table "pg_catalog.pg_attrdef"
 Column  |   Type   | Modifiers 
---------+----------+-----------
 adrelid | oid      | not null
 adnum   | smallint | not null
 adbin   | text     | 
 adsrc   | text     | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 8.3)

 Table "pg_catalog.pg_attrdef"
 Column  |   Type   | Modifiers 
---------+----------+-----------
 adrelid | oid      | not null
 adnum   | smallint | not null
 adbin   | text     | 
 adsrc   | text     | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

pg_attrdef (PostgreSQL 8.2)

 Table "pg_catalog.pg_attrdef"
 Column  |   Type   | Modifiers 
---------+----------+-----------
 adrelid | oid      | not null
 adnum   | smallint | not null
 adbin   | text     | 
 adsrc   | text     | 
Indexes:
    "pg_attrdef_adrelid_adnum_index" UNIQUE, btree (adrelid, adnum)
    "pg_attrdef_oid_index" UNIQUE, btree (oid)

文档: pg_attrdef

变更历史

示例

postgres=# CREATE TABLE foo (val TEXT DEFAULT 'bar');
CREATE TABLE
postgres=# SELECT a.*
postgres-#   FROM pg_attrdef a
postgres-#   JOIN pg_class c ON a.adrelid=c.oid
postgres-#  WHERE c.relname='foo'\x\g\x
Expanded display is on.
-[ RECORD 1 ]--------------------------------------------------------------
oid     | 16456
adrelid | 16453
adnum   | 1
adbin   | {CONST :consttype 25
                          :consttypmod -1
                          :constcollid 100
                          :constlen -1
                          :constbyval false
                          :constisnull false
                          :location 35
                          :constvalue 7 [ 28 0 0 0 98 97 114 ]}

使用 pg_get_expr() 将值 adbin 转换为人类可读的格式，例如：

postgres=# SELECT pg_catalog.pg_get_expr(a.adbin, a.adrelid, true)
postgres-# FROM pg_attrdef a
postgres-#   JOIN pg_class c ON a.adrelid=c.oid
postgres-# WHERE c.relname='foo';
 pg_get_expr
-------------
 'bar'::text
(1 row)

分类

系统目录

另请参阅

pg_attribute

反馈

提交任何关于 "pg_attrdef" 的评论、建议或更正 此处。