Question

我的表中有一个字符变化（12）字段，它是PRIMARY KEY。我跑了这个查询

SELECT * FROM bg WHERE bg_id ='470370111002'

从表中选择一行。一切看起来都不错然后我试试。

INSERT INTO csapp_center_bgs(bg_id,center_id) VALUES('470370111002',2)

bg_id上有一个外键，看起来像......

ALTER TABLE csapp_center_bgs
ADD CONSTRAINT csapp_center_bgs_bg_id_65c818f360c84dc5_fk_bg_bg_id
FOREIGN KEY (bg_id)
REFERENCES tiger.bg (bg_id) MATCH SIMPLE
ON UPDATE NO ACTION ON DELETE NO ACTION DEFERRABLE INITIALLY DEFERRED;

这是准确的错误......

    ERROR:  insert or update on table "csapp_center_bgs" violates foreign key constraint "csapp_center_bgs_bg_id_65c818f360c84dc5_fk_bg_bg_id"
DETAIL:  Key (bg_id)=(470370111002) is not present in table "bg".
********** Error **********

ERROR: insert or update on table "csapp_center_bgs" violates foreign key constraint "csapp_center_bgs_bg_id_65c818f360c84dc5_fk_bg_bg_id"
SQL state: 23503
Detail: Key (bg_id)=(470370111002) is not present in table "bg".

为什么这不起作用？！有任何想法吗？这是\ d + bg ......

  Column  |         Type          |                    Modifiers                     | Storage  | Stats target | Description 
----------+-----------------------+--------------------------------------------------+----------+--------------+-------------
 gid      | integer               | not null default nextval('bg_gid_seq'::regclass) | plain    |              | 
 statefp  | character varying(2)  |                                                  | extended |              | 
 countyfp | character varying(3)  |                                                  | extended |              | 
 tractce  | character varying(6)  |                                                  | extended |              | 
 blkgrpce | character varying(1)  |                                                  | extended |              | 
 bg_id    | character varying(12) | not null                                         | extended |              | 
 namelsad | character varying(13) |                                                  | extended |              | 
 mtfcc    | character varying(5)  |                                                  | extended |              | 
 funcstat | character varying(1)  |                                                  | extended |              | 
 aland    | double precision      |                                                  | plain    |              | 
 awater   | double precision      |                                                  | plain    |              | 
 intptlat | character varying(11) |                                                  | extended |              | 
 intptlon | character varying(12) |                                                  | extended |              | 
 the_geom | geometry              |                                                  | main     |              | 
Indexes:
    "bg_pkey" PRIMARY KEY, btree (bg_id)
    "idx_bg_geom" gist (the_geom) CLUSTER
Check constraints:
    "enforce_dims_geom" CHECK (st_ndims(the_geom) = 2)
    "enforce_geotype_geom" CHECK (geometrytype(the_geom) = 'MULTIPOLYGON'::text OR the_geom IS NULL)
    "enforce_srid_geom" CHECK (st_srid(the_geom) = 4269)
Referenced by:
    TABLE "csapp_center_bgs" CONSTRAINT "csapp_center_bgs_bg_id_65c818f360c84dc5_fk_bg_bg_id" FOREIGN KEY (bg_id) REFERENCES bg(bg_id) DEFERRABLE INITIALLY DEFERRED
Child tables: tiger_data.tn_bg
Has OIDs: no

这是csapp _...

上的\ d +

  Column   |         Type          |                           Modifiers                           | Storage  | Stats target | Description 
-----------+-----------------------+---------------------------------------------------------------+----------+--------------+-------------
 id        | integer               | not null default nextval('csapp_center_bgs_id_seq'::regclass) | plain    |              | 
 bg_id     | character varying(12) | not null                                                      | extended |              | 
 center_id | integer               | not null                                                      | plain    |              | 
Indexes:
    "csapp_center_bgs_pkey" PRIMARY KEY, btree (id)
    "csapp_center_bgs_5e94e25f" btree (bg_id)
    "csapp_center_bgs_c63f1184" btree (center_id)
Foreign-key constraints:
    "csapp_center_bgs_bg_id_65c818f360c84dc5_fk_bg_bg_id" FOREIGN KEY (bg_id) REFERENCES bg(bg_id) DEFERRABLE INITIALLY DEFERRED
    "csapp_center_bgs_center_id_360e6806f7d3fee_fk_csapp_centers_id" FOREIGN KEY (center_id) REFERENCES csapp_centers(id) DEFERRABLE INITIALLY DEFERRED
Has OIDs: no

以下是版本：

                                               version                                                
------------------------------------------------------------------------------------------------------
 PostgreSQL 9.3.5 on x86_64-unknown-linux-gnu, compiled by gcc (Ubuntu 4.8.2-19ubuntu1) 4.8.2, 64-bit

这是我的搜索路径......

search_path  
---------------
 public, tiger
(1 row)

bg在schema tiger中，csapp_center_bgs在schema public ...

Answer 1

我的第一个猜测是你正在处理名为bg的 两个不同的表。模式tiger中的一个，以及 tiger 中search_path之前的未公开模式中的另一个 - 或者search_path中不存在毕竟。

在当前db中的所有模式中查找名为bg的所有表（区分大小写）：

SELECT * FROM pg_tables WHERE tablename = 'bg';

了解search_path设置：

How does the search_path influence identifier resolution and the "current schema"

要了解Postgres数据库集群的结构：

What's the difference between a catalog and a schema in a relational database?

如果不是这样，您的索引可能已损坏。我先试试REINDEX：

REINDEX bg_pkey;

继承！

我在你添加的表定义中看到：

Child tables: tiger_data.tn_bg

怀疑带有bg_id ='470370111002'的行实际上位于子表 tiger_data.tn_bg中。但是您的FK约束引用了父表。 FK约束不是继承的如果您查询，您会得到什么：

SELECT * FROM ONLY bg WHERE bg_id ='470370111002'

如果我的假设成立，你会得到 no row 。阅读chapter Caveats on the Inheritance page of the manual。

错误：＆＃34; Key ...不存在于表＆＃34;

1 个答案:

继承！