Community Learn Tools Library Leisure
search
English
Home > Database > Mysql Tutorial > MySQL里Create Index 能否创建主键 Primary Key

MySQL里Create Index 能否创建主键 Primary Key

WBOY
Release： 2016-06-07 18:01:19
Original
1145 people have browsed it

MySQL里Create Index 能否创建主键 Primary Key

MySQL里Create Index 能否创建主键 Primary Key?
答案：

不能，必须用 Alter table 创建。

MySQL一个索引列最大允许的有效长度，不是列的所有数据都被索引的

MyISAM 是 1000字节
InnoDB 是 767 字节

注意这里是字节。
Related labels：
create index mysql primary key
source：php.cn
Previous article：Mysql LONGBLOB 类型存储二进制数据 (修改+调试+整理) Next article：Sql function 多行中的列合并为一行一列的方法
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Latest Issues
How to display only the lowest value from a result set (MYSQL) I have the following statement: selectDATE(recieved_on)asDay,round(count(*)/24)AS'average'...
From 2024-04-06 21:44:19
0
1
603
Calculate the sum of fields in another table using MySQL SQL query I have a schema like this: User table with attributes "user_id" and "userna...
From 2024-04-06 19:39:29
0
1
441
MySQL: "Select text from... as <variable here or subquery>" I have the following table with the following data: id text language 1 german text german ...
From 2024-04-06 19:25:54
0
2
529
How to group and count in MySQL? I'm trying to write a query that extracts the total number of undeleted messages sent to f...
From 2024-04-06 18:30:17
0
1
353
MySQL gets data from multiple tables I have a eg_design table which contains the following columns: and eg_domains table which ...
From 2024-04-06 18:42:44
0
2
479
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template