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2025-04-04 Update From: SLTechnology News&Howtos shulou NAV: SLTechnology News&Howtos > Database >
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How to achieve non-primary key self-growth in mysql? I believe that many inexperienced people are at a loss about this, so this article summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.
Mysql is not only the primary key can grow itself, but the column set as the key can be set to self-growing. As follows:
CREATE TABLE T1 (id INT, col1 INT auto_increment NOT NULL)
The results are as follows:
If you set the col1 column as the key, you can create self-increment.
CREATE TABLE T1 (id INT, col1 INT auto_increment NOT NULL, key (col1))
The results are as follows:
If we set id as the primary key, we can still create it successfully.
CREATE TABLE T2 (id INT PRIMARY KEY, col1 INT auto_increment NOT NULL, key (col1))
The results are as follows:
So the auto-increment column must be a key, but not necessarily a primary key. But can a table have more than one self-increasing column?
A: there can be only one self-increasing column in a table.
CREATE TABLE T3 (id INT PRIMARY KEY auto_increment, col1 INT auto_increment NOT NULL, key (col1))
The results are as follows:
After reading the above, have you mastered how to achieve non-primary key self-growth in mysql? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!
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