从数据库中删除记录

Question

嗨，请帮助我。
我有一个有很多表的数据库。我必须从整个数据库中删除其studentId不在给定10个ID中的所有记录（除了10个给定的studentID）。 studentID是表中的主键和大量表中的外键。我不确定即使其他表可能具有相同的studentID，现在我想编写一个脚本来执行此任务，这将从父表中删除所有记录以及子表（sql server 2008）。

Answer 1

对于外键约束，您必须首先从子表执行删除操作。

它会是这样的，因为你已经有了StudentID，所以父表不需要连接到父表。

Delete child1 Where studentID not in (1,2,4,5,6,77,122,123,1222,12121,99999) 
Delete child2 Where studentID not in (1,2,4,5,6,77,122,123,1222,12121,99999) 
Delete child3 Where studentID not in (1,2,4,5,6,77,122,123,1222,12121,99999) 
Delete students Where studentID not in (1,2,4,5,6,77,122,123,1222,12121,99999) 

如果你有一个“孙子”表，例如学生 - >账户 - > AccountHistory，那么你会以相反的顺序取下，例如：

Delete AccountHitory 
where AccountID not in (
    select AccountID 
    From Account 
    Where studentID in (1,2,4,5,6,77,122,123,1222,12121,99999)) 

Delete Account Where studentID not in (1,2,4,5,6,77,122,123,1222,12121,99999) 

Delete Student Where studentID not in (1,2,4,5,6,77,122,123,1222,12121,99999) 

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要找出的外键连接的层次结构，您可以使用此查询

示例表

create table student (studentid int identity primary key) 
create table student_class (id int primary key, studentid int references student(studentid)) 
create table student_class_attendance (student_classid int references student_class(id), attended datetime) 
create table invoice (id int primary key, studentid int references student(studentid), due datetime, amount money) 

查询找到链接表

;with tmp(lvl,FK,PK) As (
    SELECT 1, FK.TABLE_NAME, PK.TABLE_NAME 
    FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C 
    INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME 
    INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME 
    WHERE PK.TABLE_NAME = 'student' 
    UNION ALL 
    SELECT lvl+1, FK.TABLE_NAME, PK.TABLE_NAME 
    FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C 
    INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME 
    INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME 
    INNER JOIN tmp on tmp.FK = PK.TABLE_NAME 
) 
SELECT * 
FROM tmp 
order by lvl desc