在你的数据访问类中,例如UserRepository,你可以调用自增ID生成器。 importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Repository;@RepositorypublicclassUserRepository{@Autowiredprivate
private SequenceGeneratorService sequenceGenerator; public void addUser(String name, String email) { long userId = sequenceGenerator.generateSequence("user_seq"); User newUser = new User(userId, name, email); userRepository.save(newUser); } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12...
基于数据库的auto_increment自增ID完全可以充当分布式ID,具体实现:需要一个单独的MySQL实例用来生成ID,建表结构如下 CREATE DATABASE `SEQ_ID`; CREATE TABLE SEQID.SEQUENCE_ID ( id bigint(20) unsigned NOT NULL auto_increment, valuechar(10) NOT NULLdefault'', PRIMARY KEY (id), ) ENGINE=MyISAM; i...
我们创建拥有generateSequence()方法的SequenceGeneratorService服务 现在我们在创建新记录的时候能使用方法generateSequence() 使用UserRepository来遍历所有用户。 现在,每次创建模型的新实例时,我们都必须设置id字段。我们可以通过为Spring Data MongoDB生命周期事件创建侦听器来绕过这个过程。为此,我们将创建一个UserModelListen...
假设你希望 id 列自动生成(这称为 auto-increment/sequence/serial/generated identity column)。为此你需要将@PrimaryColumn装饰器更改为@PrimaryGeneratedColumn装饰器: import{ Entity, Column, PrimaryGeneratedColumn }from"typeorm";@Entity()exportclassPhoto {@PrimaryGeneratedColumn() ...
SERVER-76102handleRIDRangeScan() 会在递归情况下错误设置 hasCompatibleCollation SERVER-76179 每次Mongod 关闭时删除 “/var/run/mongodb/”mongod.pid” SERVER-76278 记录额外的迁移信息 SERVER-76331 将mongo-task-generator 版本升级到 0.7.5 SERVER-76378 在计算块数据块时使用估计的模拟元数据大小 SERVER-76...
A unique identifier may be required in a monotonically increasing and continuous sequential order, which is similar to the sequence functionality that is implemented by some RDBMSs. This may be achieved by implementing a solution that is based on a centralised counter document that resides in a co...
Sequence" : 1.0 }, "indexName" : "status_1_userSequence_1", "isMultiKey" : false, "isUnique" : false, "isSparse" : false, "isPartial" : false, "indexVersion" : 1, "direction" : "forward", "indexBounds" : { "status" : [ "[\"APPLY\", \"APPLY\"]" ], "userSequence" ...
这个版本的MongoDB包括了性能优异的WiredTiger存储引擎，现在默认开启。我们还引入了一个灵活的方式到Meteor...
A causally consistent client session denotes that the associated sequence of read and acknowledged write operations have a causal relationship that is reflected by their ordering. Client applications must ensure that only one thread at a time executes these operations in a client session. Applications ...