1、方式一 create table 表名 ( 字段名1 数据类型 约束, 字段名2 数据类型 约束, 。。。 constraint 外键名 foreign key(字段名) references 主表名(字段名) 级联操作); 方式2:表创建完成后添加外键 alter table 表名 add constraint 外键名 foreign key (字段1) references 表名2(字段名2)级联操作; 三...
步骤1:创建表时在字段后面直接加上索引 CREATETABLEusers(idINTPRIMARYKEY,-- 主键索引nameVARCHAR(50)UNIQUE,-- 唯一索引ageINT,INDEXname_index(name)-- 普通索引); 1. 2. 3. 4. 5. 6. PRIMARY KEY:主键索引,唯一标识每条记录 UNIQUE:唯一索引,确保字段值在表中是唯一的 INDEX:普通索引,加速数据的查询...
CREATE TABLE table1 ( column1 INT(11), column2 INT(11), PRIMARY KEY (column1) ); ALTER TABLE table1 DROP INDEX `PRIMARY`, ADD PRIMARY KEY (column1, column2); Devart Company, MySQL management tools http://www.devart.com/dbforge/mysql/ ...
PRIMARY KEY关键字用于定义列为主键。您可以使用多列来定义主键,列间以逗号分隔。 ENGINE 设置存储引擎,CHARSET 设置编码。 通过命令提示符创建表 通过mysql> 命令窗口可以很简单的创建MySQL数据表。你可以使用 SQL 语句CREATE TABLE来创建数据表。 以下为创建数据表...
You can create one table from another by adding a SELECT statement at the end of the CREATE TABLE statement: CREATE TABLE new_tbl [AS] SELECT * FROM orig_tbl; MySQL creates new columns for all elements in the SELECT. For example: ...
在create table的语句中,key和index混淆在一起,官方手册中的解释是这样: KEYis normally a synonym forINDEX. The key attributePRIMARY KEYcan also be specified as justKEYwhen given in a column definition. This was implemented for compatibility with other database systems. ...
MySQL进阶_create table篇 MySQL中create table语句的基本语法是: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [select_statement] TEMPORARY:该关键字表示用create table新建的表为临时表,此表在当前会话结束后将自动消失。临时表主要被应用于存储过程中,对于...
Create primary key when creating the table: importmysql.connector mydb = mysql.connector.connect( host="localhost", user="yourusername", password="yourpassword", database="mydatabase" ) mycursor = mydb.cursor() mycursor.execute("CREATE TABLE customers (id INT AUTO_INCREMENT PRIMARY KEY, nam...
CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition: col_name column_definition | [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... ...
-- TABLE -- Version: 1 Fragment type: 9 K Value: 6 Min load factor: 78 Max load factor: 80 Temporary table: no Number of attributes: 7 Number of primary keys: 1 Length of frm data: 296 Row Checksum: 1 Row GCI: 1 SingleUserMode: 0 ...