Java笔记 ·

springBoot生成SQL文件-基于Liquibase实现

之前的文章介绍的都是用的jpa或者Hibernate内部方法实现的,本文引入一个第三方数据库管理工具Liquibase,说到数据库版本管理软件还有Flyway,但其社区版无论是功能还是用法均简单至极,完全无法和Liquibase相比。

当项目中不使用Hibernate与jpa自动生成表时,完全可以用Liquibase管理SQL脚本的版本迭代,还可以对比数据库间的差异生成对应的差异log,其用来管理版本的log文件还可以与SQL脚本文件互转,具体强大到几何去其官网领教吧。

本文的目标是创建一个gradle的task来运行Liquibase生成增量脚本,这里需要引入其gradle插件liquibase-gradle-plugin

目录

插件基本用法

这里仅做基础介绍,详情可见其README.md文档。

1.引入插件

要将插件包含到Gradle构建中,只需将以下内容添加到build.gradle文件中:

plugins {
  id 'org.liquibase.gradle' version '2.0.1'
}

要使用较旧的Gradle 2.0样式(多模块项目好像必须用这种),请将以下内容添加到build.gradle中:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.liquibase:liquibase-gradle-plugin:2.0.1"
    }
}
apply plugin: 'org.liquibase.gradle'

2.设置classpath

该插件在运行任务时需要能够在类路径上找到Liquibase,而Liquibase需要能够在类路径中找到数据库驱动程序,更改日志解析器等。

这是通过将liquibaseRuntime依赖项添加到build.gradle文件中的依赖项块来完成的。
至少,您需要包含Liquibase本身以及数据库驱动程序:

dependencies {
  // All of your normal project dependencies would be here in addition to...
  liquibaseRuntime 'org.liquibase:liquibase-core:3.6.1'
  liquibaseRuntime 'mysql:mysql-connector-java:5.1.34'
}

3.配置插件

Liquibase命令的参数在build.gradle文件内的liquibase块中配置。

该块包含一系列“activity”,每个activity定义一系列Liquibase参数。

“activity”中的任何方法都假定为Liquibase命令行参数。例如,在活动中包含changeLogFile'myfile.groovy'--changeLogfile = myfile.groovy在命令行上执行的操作相同。在activity中包含difftypes'data'difftypes = data在命令行上执行的操作相同,等等.Liquibase文档详细说明了所有有效的命令行参数。

liquibase块还有一个可选的“runList”,它确定为每个任务运行哪些活动。如果没有定义runList,Liquibase插件将运行所有活动。注意:不保证没有runList时的执行顺序。

liquibase {
  activities {
    main {
      changeLogFile 'src/main/db/main.groovy'
      url project.ext.mainUrl
      username project.ext.mainUsername
      password project.ext.mainPassword
    }
    security {
      changeLogFile 'src/main/db/security.groovy'
      url project.ext.securityUrl
      username project.ext.securityUsername
      password project.ext.securityPassword
    }
    diffMain {
      changeLogFile 'src/main/db/main.groovy'
      url project.ext.mainUrl
      username project.ext.mainUsername
      password project.ext.mainPassword
      difftypes 'data'
    }
  }
  runList = project.ext.runList
}

多模块项目中生成增量脚本

目标将生成增量脚本的task单独抽成一个liquibase.gradle文件,在build.gradle中引入。本方案是通过对比两个数据库生成增量脚本。

1.设置build.gradle

buildscript中dependencies包含插件:

buildscript {
    ...
    dependencies {
        ...

        classpath "org.liquibase:liquibase-gradle-plugin:2.0.1"
    }
}

不然会报如下错误,原本想只在liquibase.gradle中引入,但发现在liquibase.gradle中无效:

Plugin with id 'org.liquibase.gradle' not found.

configure(rootProject)中引入插件:

configure(rootProject) {

    ...

    apply from: "${rootProject.projectDir}/gradle/liquibase.gradle"

    ...
}

2.创建liquibase.gradle

具体文件如下:

apply plugin: 'org.liquibase.gradle'

dependencies {
    liquibaseRuntime 'org.liquibase:liquibase-core:3.6.2'
    liquibaseRuntime 'org.liquibase:liquibase-groovy-dsl:2.0.1'
    liquibaseRuntime 'mysql:mysql-connector-java:5.1.34'
}

def buildTimestamp() {
    def date = new Date()
    def formattedDate = date.format('yyyyMMddHHmmss')
    return formattedDate
}

task diffDBSQL(){
    doFirst{
        File propsFile = new File("${rootProject.projectDir}/qycms-core/common/src/main/resources/application.properties")
        Properties properties = new Properties()
        properties.load(new FileInputStream(propsFile))

        def changeLogOutPutFileURL = "${rootProject.projectDir}/db/liquibase/changelog/changelog-diff-master-"+ buildTimestamp()+".yaml"
        def outputFileURL = "${rootProject.projectDir}/db/liquibase/diffSQL-"+buildTimestamp()+".sql"
        def referenceDriverURL =  "${properties.contains('parim.datasource.referenceDriver-class-name')}" == true ? "${properties.contains('parim.datasource.referenceDriver-class-name')}" : "${properties.get('spring.datasource.driver-class-name')}"

        liquibase {
            activities {
                diff {
                    driver "${properties.get('spring.datasource.driver-class-name')}"
                    url "${properties.get('spring.datasource.url')}"
                    username "${properties.get('spring.datasource.username')}"
                    password "${properties.get('spring.datasource.password')}"

                    referenceDriver "${referenceDriverURL}"
                    referenceUrl "${properties.get('qy.datasource.referenceUrl')}"
                    referenceUsername  "${properties.get('qy.datasource.referenceUsername')}"
                    referencePassword  "${properties.get('qy.datasource.referencePassword')}"

                    changeLogFile "${changeLogOutPutFileURL}"   
                    outputFile "${outputFileURL}"
                }
                runList = "diff" // 这里代表选择哪一个配置 可用参数代替
            }
        }
    }

    doLast{
        diffChangeLog.execute()
        updateSQL.execute()
    }
}

3.配置application.properties

由上面配置可知,这里将liquibase的配置属性都集中在了application.properties文件中,故在application.properties文件中配置参考的标准数据库信息,如:

qy.datasource.referenceUrl=数据库地址
qy.datasource.referenceUsername=数据库用户名
qy.datasource.referencePassword=数据库密码

若想自定义参照数据库的驱动类名可添加使用qy.datasource.referenceDriver-class-name属性字段,反之默认使用 spring.datasource.driver-class-name字段。

文件中已默认添加MySQL和Oracle的运行时驱动,若无法满足需求可自行修改为所需版本:

    liquibaseRuntime 'mysql:mysql-connector-java:5.1.46'
    liquibaseRuntime 'com.oracle:ojdbc6:12.1.0.1-atlassian-hosted'

默认在${rootProject.projectDir}/db/liquibase/changelog目录下生成diff后的changelog文件changelog-diff-master-日期.yml,如changelog-master-20181217172416.yaml。该文件用于之后生成SQL增量脚本。

默认在${rootProject.projectDir}/db/liquibase目录下生成SQL增量脚本diffSQL-日期.sql

4.使用方法

执行gradle diffDBSQL即可生成所需要的增量SQL脚本文件。

该脚本仅涉及表结构,执行涉及到的DROP的语句前,请确保该语句不是因重命名字段等产生的。

单模块项目中生成增量脚本

单模块可以如上面多模块生成方式一样对比两个数据库,也可以对比数据库与当前程序中的注解entity生成增量脚本。原因是单模块下可以直接通过配置liquibaseRuntime sourceSets.main.output依赖,将entity的classpath注入给liquibase,若多模块下有大神能找到方案,也可以使用这种方案从而免去建参照库。

这里仅介绍对比数据库与当前程序中的注解entity生成增量脚本的方案,该方案需要用到liquibase-hibernate以及一大批jpa相关的依赖,具体完整文件如下:

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'org.springframework.boot:spring-boot-gradle-plugin:2.0.3.RELEASE'
    }
}

plugins {
    id 'java'
    id 'idea'
    id 'io.franzbecker.gradle-lombok' version '1.14'
    id 'org.liquibase.gradle' version '2.0.1'
}

apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'

group 'de.bobek'
version '1.0-SNAPSHOT'

sourceCompatibility = 1.8
targetCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies {
    compile 'org.springframework.boot:spring-boot-starter-web'
    compile 'org.springframework.boot:spring-boot-starter-data-jpa'
    compile 'org.liquibase:liquibase-core'
    compile 'com.h2database:h2'
    liquibaseRuntime 'org.liquibase:liquibase-core:3.6.2'
    liquibaseRuntime 'org.liquibase.ext:liquibase-hibernate5:3.6'
    liquibaseRuntime 'mysql:mysql-connector-java:5.1.46'
    liquibaseRuntime 'org.springframework.boot:spring-boot:2.0.1.RELEASE'
    liquibaseRuntime 'org.springframework:spring-orm:5.0.5.RELEASE'
    liquibaseRuntime sourceSets.main.output
}

diff.dependsOn compileJava
diffChangeLog.dependsOn compileJava

liquibase {
    activities {
        main {
            driver 'com.mysql.jdbc.Driver'
            url 'jdbc:mysql://127.0.0.1:3306/my_database'
            username 'root'
            password ''
            changeLogFile 'src/main/resources/db/changelog/changelog-master.xml'
            referenceUrl 'hibernate:spring:de.bobek' +
                    '?dialect=org.hibernate.dialect.MySQL5Dialect' +
                    '&hibernate.physical_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy' +
                    '&hibernate.implicit_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy'
        }
    }
}

使用

gradle diffChangeLog

该方案参考资料:

liquibase插件内置任务

多模块项目的解决方案下liquibase.gradle文件的doLast中的diffChangeLog和updateSQL均属于liquibase插件中的内置任务。

命令 描述
update Updates the database to the current version.
updateSQL Writes SQL to update the database to the current version to STDOUT.
futureRollbackSQL Writes SQL to roll back the database to the current state after the changes in the changeslog have been applied.
updateTestingRollback Updates the database, then rolls back changes before updating again.
listLocks Lists who currently has locks on the database changelog.
dropAll Drops all database objects owned by the user. Note that functions, procedures and packages are not dropped (Liquibase limitation)
releaseLocks Releases all locks on the database changelog.
validate Checks the changelog for errors.
diff Writes description of differences to standard out.
diffChangeLog Writes Change Log to update the database to the reference database to standard out
snapshot Writes the current state of the database to standard out
snapshotReference Writes the current state of the referenceUrl database to standard out
clearChecksums Removes all saved checksums from the database. On next run checksums will be recomputed. Useful for "MD5Sum Check Failed" errors.
changelogSync Mark all changes as executed in the database.
changelogSyncSQL Writes SQL to mark all changes as executed in the database to STDOUT.
markNextChangesetRan Mark the next change set as executed in the database.
markNextChangesetRanSQL Writes SQL to mark the next change set as executed in the database to STDOUT.
status Outputs count (list if liquibaseCommandValue is "--verbose") of unrun change sets.
generateChangelog Writes Change Log groovy to copy the current state of the database to standard out.
unexpectedChangeSets Outputs count (list if liquibaseCommandValue is "--verbose") of changesets run in the database that do not exist in the changelog.

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