mysql_insert_id或类似的东西返回最后一个mysql UUID() [英] mysql_insert_id or something like that to return last mysql UUID()

问题描述

如何返回最后生成的UUID()(主键)-是否有类似mysql_insert_id的东西?

How do you return the last generated UUID() (primary key) - is there something like mysql_insert_id for that?

表uuidtable:

primary key: uuid uuid()
id_u (index): integer

多个id_u与主键uuid()匹配

multiple id_u matched with a primary key uuid()

插入:insert into uuidtable (uuid,id_u) values (uuid(),id)

当然，其中id是一个数字，而uuid使用

where id is a number, of course, and uuid is escaped with

 uuid 

推荐答案

为自己编写一个触发器，如下所示:

Write yourself a trigger like so:

CREATE TRIGGER ai_uuidtable
AFTER INSERT ON uuidtable
FOR EACH ROW
SET @last_uuid = NEW.uuid;

在插入之后:

SELECT @last_uuid

MySQL的用户定义变量是特定于连接的，因此您不必担心获取另一个连接的@last_uuid.

MySQL's user-defined variables are connection-specific, so you don't have to worry about getting another connection's @last_uuid.

一个关注点:如果您使用uuid作为键，则为了使其发挥最大性能，应将其存储为16字节的binary字段，而不是36字节的char场地.如果您确实要使用MySQL的UUID()算法，请去除连字符并UNHEX()

One point of concern: If you're using the uuid as a key, in order for it to be maximally performant, it should be stored as a 16-byte binary field and not a 36-byte char field. If you really want to use MySQL's UUID() algorithm, strip out the hyphens and UNHEX() it:

UNHEX( REPLACE( UUID(), '-', '' ) )

此外:PostgreSQL实际上具有UUID数据类型(但没有内置的UUID()函数)，这意味着您不必重新HEX()字段即可避免在终端中获取二进制垃圾在SELECT.

Aside: PostgreSQL actually has a UUID data type (but no built-in UUID() function), which just means you don't have to re-HEX() the field in order to avoid getting binary garbage in your terminal on SELECT.

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