TDSQL PostgreSQL版创建和删除外键-开发指南-文档中心-腾讯云

创建外键
postgres=# create table t_p(f1 int not null,f2 int ,primary key(f1));
create table t_f(f1 int not null,f2 int );NOTICE:  Replica identity is needed for shard table, please add to this table through "alter table" command.
CREATE TABLE
postgres=# create table t_f(f1 int not null,f2 int );
NOTICE:  Replica identity is needed for shard table, please add to this table through "alter table" command.
CREATE TABLE
postgres=# ALTER TABLE t_f ADD CONSTRAINT t_f_f1_fkey FOREIGN KEY (f1) REFERENCES t_p (f1);
ALTER TABLE
postgres=# 
外键只是同一个节点内约束有效果，所以外键字段和对应主键字段必须都是表的分布键，否则由于数据分布于不同的节点内会导致更新失败。
删除外键
postgres=# \\d+ t_f
                  Table "public.t_f"
 Column |  Type  | Collation | Nullable | Default | Storage | Stats target | Description 
--------+---------+-----------+----------+---------+---------+--------------+-------------
 f1   | integer |      | not null |     | plain  |        | 
 f2   | integer |      |      |     | plain  |        | 
Foreign-key constraints:
  "t_f_f1_fkey" FOREIGN KEY (f1) REFERENCES t_p(f1)
Distribute By: SHARD(f1)
Location Nodes: ALL DATANODES
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postgres=# ALTER TABLE t_f drop constraint t_f_f1_fkey;
ALTER TABLE
postgres=# \\d+ t_f
                  Table "public.t_f"
 Column |  Type  | Collation | Nullable | Default | Storage | Stats target | Description 
--------+---------+-----------+----------+---------+---------+--------------+-------------
 f1   | integer |      | not null |     | plain  |        | 
 f2   | integer |      |      |     | plain  |        | 
Distribute By: SHARD(f1)
Location Nodes: ALL DATANODES 
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创建和删除外键

本页目录：

创建外键

删除外键
