CREATE TABLE employees ( employee_id INT NOT NULL, first_name VARCHAR(50), last_name VARCHAR(50), email VARCHAR(100), PRIMARY KEY (employee_id) USING BTREE ); 在上面的示例中,employee_id列被定义为主键,并且明确指定了使用B树索引(虽然在MySQL中,主键默认就是使用B树索引的,但显式指定可以增加代...
PRIMARY KEY (`id`) USING BTREE,指定id列为主键，使用B树作为索引。
`sf` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) USING BTREE, KEY `id` (`id`) USING BTREE ) ENGINE=InnoDB AUTO_INCREMENT=7974 DEFAULT CHARSET=utf8 primary key use btree 是什么含义了解一下
`sf` varchar(255) DEFAULT NULL, PRIMARY KEY (`id`) USING BTREE, KEY `id` (`id`) USING BTREE ) ENGINE=InnoDB AUTO_INCREMENT=7974 DEFAULT CHARSET=utf8 primary key use btree 是什么含义了解一下
Mysql中key 、primary key 看见建表语句,如下: PRIMARY KEY (`id`), KEY `uniq_jd_pin` (`jd_pin`) USING BTREE, KEY `uniq_phone_jd_pin` (`phone`,`jd_pin`) USING BTREE, KEY `idx_sync_state` (`sync_state`) USING BTREE “Key”是什么, 意思咧?
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The name of the primary key. column1, column2, ... column_n The columns that make up the primary key. Example Let's look at an example of how to create a primary key using the CREATE TABLE statement in MySQL. CREATE TABLE contacts ( contact_id INT(11) NOT NULL AUTO_INCREMENT, las...
The columns that make up the primary key. Example Let's look at an example of how to create a primary key using the CREATE TABLE statement in MariaDB. CREATE TABLE websites ( website_id INT(11) NOT NULL AUTO_INCREMENT, website_name VARCHAR(25) NOT NULL, server_name VARCHAR(20), cr...
PostgreSQL primary key examples Let’s explore some examples of using the PostgreSQL primary key. 1) Creating a table with a primary key that consists of one column The following statement creates a table with a primary key that consists of one column: CREATE TABLE orders( order_id SERIAL PR...
Key_name:PRIMARY Seq_in_index: 1 Column_name: my_row_id Collation: A Cardinality: 0 Sub_part:NULL Packed:NULL Null: Index_type: BTREE Comment: Index_comment: Visible: YES Expression:NULL 1 rowinset(0.01 sec) To hide the Generated Invisible Primary Key (GIPK) information in the SHOW an...