sql - 查询表的外键关系

Question

对于给定的表“foo”，我需要一个查询来生成一组具有指向 foo 的外键的表。我正在使用 Oracle 10G。

Answer 1

这应该有效（或接近的东西）：

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>'); 

Answer 2

下面的语句应该给孩子们和他们所有的后代。我已经在 Oracle 10 数据库上对其进行了测试。

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

Answer 3

以下是如何进一步执行 Mike 的查询以从约束名称中获取列名称：

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>'));

Answer 4

链接到Oracle 数据库在线文档

您可能想要探索数据字典视图。他们有前缀：

• 用户
• 全部
• 数据库管理员

样本：

select * from dictionary where table_name like 'ALL%' 

---

继续 Mike 的示例，您可能希望生成脚本来启用/禁用约束。我只修改了第一行中的“选择”。

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>');

Answer 5

我知道现在回答有点晚了，但还是让我回答吧。上面的一些答案非常复杂，因此这里是一个更简单的方法。

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'

Answer 6

下载 10G 的 Oracle 参考指南，其中解释了数据字典表。

上面的答案很好，但请查看可能与约束相关的其他表。

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

最后，获得一个像 Toad 或 SQL Developer 这样的工具，它可以让你在 UI 中浏览这些东西，你需要学习使用表格，但你也应该使用 UI。

Answer 7

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;   

Answer 8

select      acc.table_name, acc.constraint_name 
from        all_cons_columns acc
inner join all_constraints ac
    on acc.constraint_name = ac.constraint_name
where       ac.r_constraint_name in (
    select  constraint_name
    from    all_constraints
    where   table_name='yourTable'
    );

Answer 9

一张表的所有约束

select 

    uc.OWNER,
    uc.constraint_name as TableConstraint1,
    uc.r_constraint_name as TableConstraint2,
    uc.constraint_type as constrainttype1,
    us.constraint_type as constrainttype2,
    uc.table_name as Table1,us.table_name as Table2,
    ucc.column_name as TableColumn1, 
    uccs.column_name as TableColumn2
from user_constraints uc
    left outer join user_constraints us on uc.r_constraint_name = us.constraint_name
    left outer join USER_CONS_COLUMNS ucc on ucc.constraint_name = uc.constraint_name
    left outer join USER_CONS_COLUMNS uccs on uccs.constraint_name = us.constraint_name
where uc.OWNER ='xxxx' and uc.table_name='xxxx' 

Answer 10

在这里加上我的两分钱。

此查询将返回具有子列和父列的所有外键，即使在多个列上有外键时也能完美匹配：

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 AND b.position = a.position
WHERE c.constraint_type = 'R'

（灵感来自@arvinq aswer）