One 、 Preface

The previous chapters have been implemented mysql、MongoDB、redis and Activiti Implementation scheme of multi tenant switch , This chapter will continue to learn Flyway Multi data source implementation scheme of database version management tool .Flyway It is a database version management tool that is independent of database application management and tracks database changes . Use Flyway Can be like Git Manage code like that sql Script , Can achieve different environments sql Script auto update , Developers submit as they submit code sql Update script , The database script is automatically updated when the program is published , It saves the trouble of operation and maintenance personnel collecting and deploying scripts , Development environment validation script , Deployed in the test environment, it can be upgraded automatically . And the update process can be traced , at present Flyway Support a lot of databases , common MySQL、MariaDB、Oracle All support .

If it is just a script upgrade of a database , This use Flyway It's simple , But if you want to upgrade multiple databases of multi tenancy , We need help from Springboot Of AbstractRoutingDataSource, When the program starts, connect the databases of different tenants to upgrade the database scripts .

Two 、 Implementation scheme

The implementation is simple , All we need to do is Flyway When configuring, use our customized data source .

1、 First of all, because we already have MySQL Multi data source support for ,Flyway The data source can be reused

2、 because Flyway When initializing, you need to pass in a data source , We can MySQL The data source of .

3、 Finally, traverse all data sources , perform Flyway Of migrate Operation completes the upgrade function of database script .

3、 ... and 、 Get ready

To demonstrate simplicity , We need to prepare some database upgrades sql Script , The first is the script file that each tenant needs to upgrade , Then the tenant tenant_one and tenant_two Their own upgrade script files .

Script files to be executed by each tenant V1.1__create_test_table.sql, Create a test surface ：