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本文主要内容:
show index from tb_name
例如:
show index from springdemo.blog;
ALTER TABLE `table` ADD INDEX `product_id` (`product_id`)
# 创建唯一索引
alter table tb_name add unique index `unique_idsrc_caffeversion` (`id_src`, `caffe_version`)
#多列索引
ALTER TABLE `table` ADD INDEX `index_name` (`col1`,`col2`)
# add primary key 添加主键
ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` )
在创建表的时候,这两个关键词没什么区别,相当于同义词
What are differences between Index v.s. Key in MySQL
CREATE TABLE tasks (
task_id INT UNSIGNED NOT NULL AUTO_INCREMENT,
INDEX parent (parent_id),
....
# However I found a code using KEY instead of INDEX as following.
...
KEY order_date (order_date)
...
There’s no difference. They are synonyms.This was implemented for compatibility with other database systems.