• Specifying the CHARACTER SET binary attribute for a character string data type causes the column to be created as the corresponding【ˌkɔːrəˈspɑːndɪŋ相应的;相关的;符合的;】 binary string data type: CHAR becomes BINARY, VARCHAR becomes VARBINARY, and TEXT becomes BLOB....
还有拉丁文,日文,韩文,中文,都可以是组成字符串的元素。 字符串类型有哪些:char/varchar/ binary/varbinary/blob/text/enum/set/ The string data types are 11.3.2 The CHAR and VARCHAR Typesdev.mysql.com/doc/refman/8.0/en/char.html 官方文档贴在上面了。我也会写一些自己的理解。 对于字符串列(CHA...
三、String Data Types -字符类型 CHAR (固定长度 ) VARCHAR(可变长度) BINARY VARBINARY BLOB 和 TEXT ENUM 枚举 SET 集合(最多64个成员) 其他类型 Spatial Data Types JSON Data Type mysql手册:https://dev.mysql.com/doc/refman/5.7/en/data-types.html...
此类备份适用于需要在出现问题时快速恢复的大型重要数据库。 逻辑备份保存表示为逻辑数据库结构(CREATE DATABASE, CREATE TABLE语句)和内容(INSERT语句或分隔文本文件)的信息。此类备份适用于较少量的数据,您可以在其中编辑数据值或表结构,或在不同的计算机体系结构上重新创建数据。 在线与离线备份 在MySQL服务器运行时...
The string data types areCHAR,VARCHAR,BINARY,VARBINARY,BLOB,TEXT,ENUM, andSET. In some cases, MySQL may change a string column to a type different from that given in aCREATE TABLEorALTER TABLEstatement. SeeSection 15.1.20.7, “Silent Column Specification Changes”. ...
In MySQL there are three main data types: string, numeric, and date and time. String Data Types Data typeDescription CHAR(size)A FIXED length string (can contain letters, numbers, and special characters). Thesizeparameter specifies the column length in characters - can be from 0 to 255. De...
The string data types areCHAR,VARCHAR,BINARY,VARBINARY,BLOB,TEXT,ENUM, andSET. In some cases, MySQL may change a string column to a type different from that given in aCREATE TABLEorALTER TABLEstatement. SeeSection 13.1.18.6, “Silent Column Specification Changes”. ...
数字类型/numeric types 日期和时间/date and time types 字符类型/string (character and byte) types 另外还包含两个没那么常用的大类: 特殊类型/spatial types JSON 继续之前,先来看一些单位上的约定和概念, M:根据具体不同的类型,其表示的意思不一样,见下方关于这个参数的讨论。
String Type (字符类型) 1、CHAR和VARCHARCHAR是固定字符长度,且最大字符长度为255=2e8-1,处理速度比VARCHAR快,但容易浪费存储空间。如CHAR(10)表示固定分配10个字符长度存储空间,当存储'PHP'时,就浪费了7个字符长度的存储空间。对于字符后尾的空格,CHAR需要做处理。VARCHAR是可变长度,根据字符实际长度分配存储空间...
MySQL has the following string data types: CHAR VARCHAR BINARY VARBINARY BLOB TEXT ENUM SET Char ACHARis a fixed length character data type. It is declared with a length,CHAR(x), where x can be between 0 to 255.CHARalways uses the same amount of storage space per entry. In case we sp...