SELECT *
FROM information_schema.constraint_table_usage
WHERE table_name = 'your_table'

或者，您可以使用pg_constraint来检索此信息

select n.nspname as schema_name,t.relname as table_name,c.conname as constraint_name
from pg_constraint c
  join pg_class t on c.conrelid = t.oid
  join pg_namespace n on t.relnamespace = n.oid
where t.relname = 'your_table_name';

然后可以运行所需的ALTER TABLE语句：

ALTER TABLE your_table DROP CONSTRAINT constraint_name;

当然你可以让查询返回完整的alter语句：

SELECT 'ALTER TABLE '||table_name||' DROP CONSTRAINT '||constraint_name||';'
FROM information_schema.constraint_table_usage
WHERE table_name in ('your_table','other_table')

如果有多个具有相同表的模式，请不要忘记在WHERE子句(和ALTER语句)中包含table_schema。