sql-server - 添加新列并设置外键关系

Question

我想在 CDRLive 中添加一个新列“IPkey”，它是 ACIPin 中的主键“pkey”。pkey 为 bigint，不为 null。

ALTER TABLE CDRLive ADD IPkey bigint NOT NULL
go
ALTER TABLE CDRLive
ADD CONSTRAINT CDRLive_IPkey FOREIGN KEY(IPkey) REFERENCES ACIPin(pkey) 

失败。错误:

Msg 4901, Level 16, State 1, Line 2
ALTER TABLE only allows columns to be added that can contain nulls, or have a DEFAULT     definition specified, or the column being added is an identity or timestamp column, or alternatively if none of the previous conditions are satisfied the table must be empty to allow addition of this column. Column 'IPkey' cannot be added to non-empty table 'CDRLive' because it does not satisfy these conditions.
 Msg 1769, Level 16, State 1, Line 1

 Foreign key 'CDRLive_IPkey' references invalid column 'IPkey' in referencing table 'CDRLive'.
 Msg 1750, Level 16, State 0, Line 1
 Could not create constraint. See previous errors.

Answer 1

如果您希望列具有 NOT NULL 约束，则需要按以下顺序执行。

1. ALTER TABLE CDRLive ADD IPkey bigint NULL
去
2. 在该列中填写您喜欢的数据。
3. ALTER TABLE CDRLive ADD IPkey bigint NOT NULL
去
4. 更改表 CDRLive
添加约束 CDRLive_IPkey 外键(IPkey)引用 ACIPin(pkey)