CREATE TABLE uuid_test(uuid CHAR(36),user VARCHAR(12)); INSERT INTO uuid_test VALUES (UUID(),'John'); SELECT * FROM uuid_test; +---+---+ | uuid | user | +---+---+ | 8c47366f-d8ec-11de-9e87-1102d62d5d4b | John | +---+---+ Others (or the manual) may be able ...
Status:OpenImpact on me: None Category:MySQL ServerSeverity:S4 (Feature request) Version:OS:Any Assigned to:CPU Architecture:Any [20 Apr 2014 9:56] Jassim Rahma Description:I suggest the following improvement: Allow UUID as default value for a columnHow to repeat:it's a suggetion...
--使用原生的uuid作为主键 create tabletest_uuid(id_binvarchar(36)PRIMARYKEY,namevarchar(200))ENGINE=InnoDBDEFAULTCHARSET=utf8;--使用重组后的uuid做为主键 create tabletest_uuid_ordered(id_binbinary(16)PRIMARYKEY,namevarchar(200))ENGINE=InnoDBDEFAULTCHARSET=utf8; 2)在mysql中创建转换函数uuidtobin 代码...
在MySQL数据库中,我需要将一些UUID列(BINARY(16))转换为VARCHAR。我想以规范的形式,而不是以字节的形式来转换它们。在Postgres,这就足够了: ALTER COLUMN my_uuid_columnMySQL等效值返回一个错误string value: '\x...' for column 'my_uuid_column' at row 1 即使它 浏览...
问题一:UUID的长度问题 UUID的长度为36个字符。假设数据库的字符集为UTF8,那么UUID的最大长度为2+3*26=110字节。如果这样的UUID作为主键的话,不仅会是主键的尺寸很大,而且会使二级索引的尺寸变大,原因是MySQL中的二级索引的value存的是PRIMARY KEY。由于主键和二级索引的尺寸很大,所以不利于在内存中操作 ...
When inserting a new row, the default value for a column with an expression default can be inserted either by omitting the column name or by specifying the column asDEFAULT(just as for columns with literal defaults): mysql>CREATETABLEt4(uidBINARY(16)DEFAULT(UUID_TO_BIN(UUID()));mysql>INSER...
UUID() 返回一个通用唯一标识符(UUID),其产生的根据是《DCE1.1: 远程过程调用》(附录A)CAE (公共应用软件环境)的说明,该作品于1997年10月由TheOpen Group 出版(文件编号C706, VALUES(col_name) 在一个INSERT… ON DUPLICATE KEY UPDATE …语句中,你可以在UPDATE子句中使用VALUES(col_name)函数,用来访问来自该...
UUID() USER() FOUND_ROWS() SYSDATE() (除非启动时启用了 --sysdate-is-now 选项) INSERT ... SELECT 会产生比 RBR 更多的行级锁 复制需要进行全表扫描(WHERE 语句中没有使用到索引)的 UPDATE 时,需要比 RBR 请求更多的行级锁 对于有 AUTO_INCREMENT 字段的 InnoDB表而言,INSERT 语句会阻塞其他 INSERT...
`log_file_uuid` varchar(64) DEFAULT NULL COMMENT 'LOGO文件的文件中心uuid(NULL表示系统默认头像)', `logo_file_url` varchar(1023) DEFAULT NULL COMMENT 'LOGO文件的OSS存储原始URL(NULL表示系统默认头像)', `disable` int(2) DEFAULT NULL COMMENT '禁用状态:0-激活/未禁用,1-已禁用', `remarks` varc...
For this post, I’ve rearranged the timestamp part of UUID (Universal Unique Identifier) and did some benchmarks. Many people store UUID as char (36) and use as row identity value (PRIMARY KEY) because it is unique across every table, every database and every server and allow easy merg...