在数据库里面使用TRUNCATE命令截断一个表的数据时，遇到如下错误
SQL >TRUNCATE TABLE ESCMOWNER.SUBX_ITEM
ORA-02266: unique/primary keys in table referenced by enabled foreign keys
有时候对应的中文错误提示为：ORA-02266: 表中的唯一/主键被启用的外部关键字引用，一般出现这个错误，是因为表中的主键被其它表的外键所引用，导致删除数据时出错。
此时，你可以通过下面脚本查看一下涉及该表主键的外键约束信息。
as org_table_name,
as org_constraint_name,
as org_constriant_type,
as org_colun_name,
as ref_table_name,
as ref_constraint_type,
as ref_constraint_name,
as ref_column_name
from dba_constraints c1,
10: dba_constraints c2,
11: dba_cons_columns n1,
12: dba_cons_columns n2
'OWNER_NAME'
'TABLE_NAME'
and n1.constraint_name = c1.constraint_name
and n1.owner = c1.owner
'R'
and c2.r_constraint_name = c1.constraint_name
and n2.owner = c2.owner
and n2.constraint_name = c2.constraint_name;