如何将序列列添加到具有记录的现有表中

I had created a new table named USERLOG with two fields from a previous VIEW. The table already consist of about 9000 records. The two fields taken from the VIEW, i.e. weblog_views consist of IP (consists of IP address), and WEB_LINK (consists of URL). This is the code I used,

我创建了一个名为USERLOG的新表，其中包含以前视图中的两个字段。该表已包含约9000条记录。从视图获取的两个字段，即weblog_views由IP(包含IP地址)和WEB_LINK(包含URL)组成。这是我用过的代码，

    CREATE TABLE USERLOG
    AS
    SELECT C_IP, WEB_LINK FROM weblog_views;

I want to add another column to this table called the USER_ID, which would consists of a sequence starting with 1 to 9000 records to create a unique id for each existing rows. I need help with this part. I'm using Oracle SQL Developer: ODMiner version 3.0.04. I tried using the AUTO-INCREMENT option,

我想向这个名为USER_ID的表中添加另一列，该列由一个序列组成，从1到9000条记录开始，为每个现有的行创建唯一的id。这部分我需要帮助。我使用Oracle SQL Developer: ODMiner版本3.0.04。我尝试使用自动递增选项，

    ALTER TABLE USERLOG
    ADD USER_ID INT UNSIGNED NOT NULL AUTO_INCREMENT;

But I get an error with this,

但是我得到了一个错误，

    Error report:
    SQL Error: ORA-01735: invalid ALTER TABLE option
    01735. 00000 -  "invalid ALTER TABLE option"

So, I would really appreciate any help that I can get!

所以，我真的很感激我能得到的任何帮助!

2 个解决方案

#1

You would need to add a column

您需要添加一个列

ALTER TABLE userlog
  ADD( user_id number );

create a sequence

创建一个序列

CREATE SEQUENCE user_id_seq
  START WITH 1
  INCREMENT BY 1
  CACHE 20;

Update the data in the table

更新表中的数据。

UPDATE userlog
   SET user_id = user_id_seq.nextval

Assuming that you want user_id to be the primary key, you would then add the primary key constraint

假设您希望user_id是主键，那么您将添加主键约束

ALTER TABLE userlog
  ADD CONSTRAINT pk_user_id PRIMARY KEY( user_id );

If you want to use the sequence to automatically add the user_id when you do an INSERT (the other option would be to specifically reference user_id_seq.nextval in your INSERT statements, you would also need a trigger

如果您希望使用序列在进行插入时自动添加user_id(另一个选项是专门引用user_id_seq)。在INSERT语句中，还需要一个触发器

CREATE OR REPLACE TRIGGER trg_userlog_user_id
  BEFORE INSERT ON userlog
  FOR EACH ROW
BEGIN
  :new.user_id := user_id_seq.nextval;
END;

#2

In addition to Justin's excellent answer you might want to prevent NULL values for your user_id in the future (as they could still be caused by UPDATE statements). Therefore, execute the following statement at the end:

除了Justin的出色回答之外，您可能希望在将来防止user_id的空值(因为它们仍然可能是由UPDATE语句引起的)。因此，在最后执行以下语句:

ALTER TABLE userlog MODIFY(user_id number NOT NULL);

修改表userlog修改(user_id号不为空);

#1