数据库迁移 在软件开发中,我们有svn、git这样的版本管理器帮我们管理源代码,我们可以很容的查看我们当前代码的版本,更新新版本代码、回滚到旧版本等等操作。如果我们不使用版本管理器进行源代码管理,维护代码将是一项十分痛苦的工作。 开发过程中,改变
数据库迁移
在软件开发中,我们有svn、git这样的版本管理器帮我们管理源代码,我们可以很容的查看我们当前代码的版本,更新新版本代码、回滚到旧版本等等操作。如果我们不使用版本管理器进行源代码管理,维护代码将是一项十分痛苦的工作。
开发过程中,改变的可能不仅仅是代码本身,随着业务需求的改变、技术设计的改变,我们数据库的schema也可能发生改变,数据库表中的某些值也可能发生改变。如果数据库相关的信息没有“版本管理”会出现什么问题呢?
假设我们项目中,有多个dev同时进行开发,在Build Pipeline上,有分为了Dev、CI、Test、Production这么几个不同的环境:
Java中,我们也有一些可选的工具。Flyway就是其中挺不错的一个http://flywaydb.org/
类似Flyway这样的工具基本原理都非常简单,数据库版本的升级都是通过SQL或者Java代码来完成。
每执行一次升级或者更新,数据库中就会把这个操作的版本号记录下来。这样就可以非常容易的判断出,当前数据库处于哪个版本。
使用Flyway
Flyway的官方文档已经做得比较详细了,大家照着做做,一下就明白了。
Flyway First Step: http://flywaydb.org/getstarted/firststeps/api.html
for Java

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MySQL view is a virtual table based on SQL query results and does not store data. 1) Views simplify complex queries, 2) Enhance data security, and 3) Maintain data consistency. Views are stored queries in databases that can be used like tables, but data is generated dynamically.

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MySQL partitioning improves performance and simplifies maintenance. 1) Divide large tables into small pieces by specific criteria (such as date ranges), 2) physically divide data into independent files, 3) MySQL can focus on related partitions when querying, 4) Query optimizer can skip unrelated partitions, 5) Choosing the right partition strategy and maintaining it regularly is key.

How to grant and revoke permissions in MySQL? 1. Use the GRANT statement to grant permissions, such as GRANTALLPRIVILEGESONdatabase_name.TO'username'@'host'; 2. Use the REVOKE statement to revoke permissions, such as REVOKEALLPRIVILEGESONdatabase_name.FROM'username'@'host' to ensure timely communication of permission changes.


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