Oracle外键查询

Oracle外键查询

有时候我们维护数据库需要知道某个表的字段被哪些表的外键关联了，可以用下面的sql语句进行查询：

SELECT
    uc.table_name AS "引用表名",
    uc.constraint_name AS "外键约束名",
    ucc.column_name AS "外键字段"
FROM
    user_constraints uc
JOIN
    user_cons_columns ucc
    ON uc.constraint_name = ucc.constraint_name
WHERE
    uc.constraint_type = 'R'
    AND uc.r_constraint_name IN (
        SELECT constraint_name
        FROM user_constraints
        WHERE table_name = 'SM_USER'
        AND constraint_type IN ('P', 'U')  -- 主键或唯一约束
    )
ORDER BY
    uc.table_name;

还有可能需要查询外键在哪个表：

SELECT table_name
FROM all_constraints
WHERE constraint_name = '外键名称'
AND constraint_type = 'R';