一 ：在系统表中查询该表的约束键名称
select * from user_constraints where table_name = 'TB_INFOSTAT_TRAINCONFERENCE'
二：在系统表中查询该约束的关联表和关联字段
select b.table_name,b.column_name from user_constraints a inner join user_cons_columns b
on a.constraint_name = b.constraint_name
where a.r_constraint_name='SYS_C0047697'