查询表的外键关系

这应该是有效的(或接近的):

select table_name
from all_constraints
where constraint_type='R'
and r_constraint_name in 
  (select constraint_name
  from all_constraints
  where constraint_type in ('P','U')
  and table_name='<your table here>'); 

下面的语句将给出孩子及其所有后代。我在Oracle10数据库上测试过它。

SELECT  level, main.table_name  parent,
    link.table_name child
FROM    user_constraints main, user_constraints link    
WHERE   main.constraint_type    IN ('P', 'U')
AND link.r_constraint_name  = main.constraint_name
START WITH main.table_name  LIKE UPPER('&&table_name')
CONNECT BY main.table_name = PRIOR link.table_name
ORDER BY level, main.table_name, link.table_name

以下是如何进一步了解Mike的问题 列名 从约束名称:

select * from user_cons_columns
where constraint_name in (
  select constraint_name 
  from all_constraints
  where constraint_type='R'
  and r_constraint_name in 
    (select constraint_name
    from all_constraints
    where constraint_type in ('P','U')
    and table_name='<your table name here>'));

链接到 Oracle Database Online Documentation

您可能想探索 Data Dictionary views . 它们有前缀:

• 用户
• 所有
• 数据库管理员

样品:

select * from dictionary where table_name like 'ALL%' 

继续Mike的示例,您可能希望生成脚本以启用/禁用约束。我只修改了第一行的“select”。

select  'alter table ' || TABLE_NAME || ' disable constraint ' || CONSTRAINT_NAME || ';'
from all_constraints
where constraint_type='R'
and r_constraint_name in 
  (select constraint_name
  from all_constraints
  where constraint_type in ('P','U')
  and table_name='<your table here>');

我知道现在回答有点晚,不过还是让我来回答吧,上面的一些答案很复杂,所以这里有一个更简单的答案。

       `SELECT a.table_name child_table, a.column_name child_column, a.constraint_name, 
       b.table_name parent_table, b.column_name parent_column
       FROM all_cons_columns a
       JOIN all_constraints c ON a.owner = c.owner AND a.constraint_name = c.constraint_name
       join all_cons_columns b on c.owner = b.owner and c.r_constraint_name = b.constraint_name
       WHERE c.constraint_type = 'R'
       AND a.table_name = 'your table name'`

select distinct table_name, constraint_name, column_name, r_table_name, position, constraint_type 
from (
    SELECT uc.table_name, 
    uc.constraint_name, 
    cols.column_name, 
    (select table_name from user_constraints where constraint_name = uc.r_constraint_name) 
        r_table_name,
    (select column_name from user_cons_columns where constraint_name = uc.r_constraint_name and position = cols.position) 
        r_column_name,
    cols.position,
    uc.constraint_type
    FROM user_constraints uc
    inner join user_cons_columns cols on uc.constraint_name = cols.constraint_name 
    where constraint_type != 'C'
) 
start with table_name = '&&tableName' and column_name = '&&columnName'  
connect by nocycle 
prior table_name = r_table_name 
and prior column_name = r_column_name;   

下载Oracle参考指南(10g),其中介绍了数据字典表。

上面的答案是好的,但请查看其他与约束相关的表格。

SELECT * FROM DICT WHERE TABLE_NAME LIKE '%CONS%';

最后,获得一个工具,比如toad或sql developer,它允许您在一个UI中浏览这些东西,您需要学习使用表,但是您也应该使用一个UI。