MySQL stores information in different formats. It allows different types of data to be used in different ways. The main types of data arecharacter, numerical, and date and time. When you create a database, you tell MySQL what kind of data to expect in a particular column by using the My...
MySQL 不区分大小写 操作数据库 中括号可选操作、大括号必选操作 创建数据库 CREATE DATABASE [IF NOT EXISTS] westos; 删除数据库 DROP DATABASE [IF EXISTS] westos; 使用数据库 -- 如果表或字段名是一个特殊字符,就需要添加: tab 键上面的 ` use school; -- 切换数据库 查看数据库 SHOW DA...
[root@box3~]# mysql -udba -pdba -h172.16.20.51WelcometotheMySQLmonitor.Commandsendwith;or\g.mysql>createdatabasebiz_db;ERROR1044(42000):Accessdeniedforuser'dba'@'%'todatabase'biz_db'mysql>createdatabasedb02;ERROR1044(42000):Accessdeniedforuser'dba'@'%'todatabase'db02'mysql>createdatabase...
13.9 Using Data Types from Other Database Engines To facilitate the use of code written for SQL implementations from other vendors, MySQL maps data types as shown in the following table. These mappings make it easier to import table definitions from other database systems into MySQL. ...
1、数据库:database,存数据的仓库;高效的存储和处理数据的介质(介质主要有磁盘和内存)。 2、数据库分类: <1>基于介质的不同进行分类: (1) 关系型数据库(SQL): 大型:Oracle,DB2; 中型:SQL-SERVER,Mysql;小型:access等。 (2)非关系型数据库(NoSQL:Not Only SQL):memcached,mongodb,redis ...
MySQL supports these groups of data types: Numeric Date & time String JSON Choosing the right data types for columns is a part of the initial design of the database. Data types ensure the correctness of the data provided. They ensure that the data is used in a meaningful way. This is ...
Document Store for developing both SQL and NoSQL document applications using a single database. SQL Roles for granting and denying permissions to groups of users, greatly reducing the security workload. OpenSSL as the default TLS/SSL library in MySQL. Default to utf8mb4 character set for richer...
6)drop database testdb; #删除数据库 7)SHOW INDEX FROM 数据表:显示数据表的详细索引信息,包括PRIMARY KEY(主键) 1、创建数据库 1#创建数据库23mysql> create database testdab charset"utf8";4Query OK, 1 row affected (0.23sec)56mysql>show databases;7+---+8| Database |9+---+10| informatio...
MySQL Data Types (Version 8.0) Each column in a database table is required to have a name and a data type. An SQL developer must decide what type of data that will be stored inside each column when creating a table. The data type is a guideline for SQL to understand what type of ...
Document Storefor developing both SQL and NoSQL document applications using a single database. SQL Rolesfor granting and denying permissions to groups of users, greatly reducing the security workload. OpenSSLas the default TLS/SSL library in MySQL. ...