grails - Grails 3数据库迁移

Question

我将应用程序更新为grails 3.1.9，但数据库迁移插件遇到问题。

我的生产application.yml看起来像这样:

   production:
        dataSource:
                driverClassName: org.postgresql.Driver
                dialect: org.hibernate.dialect.PostgreSQLDialect
                dbCreate: none
                url: jdbc:postgresql://localhost:5432/something
                username: postgres
                password: postgres
                properties:

我的build.gradle看起来像这样:

buildscript {
 dependencies {
        classpath 'org.grails.plugins:database-migration:2.0.0.RC4'
    }
}

    dependencies {
        compile 'org.liquibase:liquibase-core:3.4.1'
        compile 'org.grails.plugins:database-migration:2.0.0.RC4'
    }

这是变更日志的开始:

databaseChangeLog = {

    changeSet(author: "michal (generated)", id: "1472650791344-1") {
        createTable(tableName: "appointment") {
            column(autoIncrement: "true", name: "id", type: "BIGINT") {
                constraints(primaryKey: "true", primaryKeyName: "appointmentPK")
            }

            column(name: "version", type: "BIGINT")

            column(name: "customer_id", type: "BIGINT")

            column(name: "duration", type: "BLOB(255)")

            column(name: "note", type: "CLOB")

            column(defaultValueComputed: "0", name: "personal_available", type: "BOOLEAN")

            column(defaultValueComputed: "0", name: "personal_booked", type: "BOOLEAN")

            column(name: "provider_id", type: "BIGINT")

            column(name: "start_time", type: "BLOB(255)")

            column(name: "url", type: "VARCHAR(255)")
        }
    }

在生产模式下运行应用程序时，出现此错误。

SEVERE 8/31/16 3:41 PM: liquibase: changelog.groovy: changelog.groovy::1472650791344-1::michal (generated): Change Set changelog.groovy::1472650791344-1::michal (generated) failed.  Error: ERROR: relation "appointment" already exists [Failed SQL: CREATE TABLE public.appointment (id BIGSERIAL NOT NULL, version BIGINT, customer_id BIGINT, duration BYTEA, note TEXT, personal_available BOOLEAN DEFAULT 0, personal_booked BOOLEAN DEFAULT 0, provider_id BIGINT, start_time BYTEA, url VARCHAR(255), CONSTRAINT "appointmentPK" PRIMARY KEY (id))]
liquibase.exception.DatabaseException: ERROR: relation "appointment" already exists [Failed SQL: CREATE TABLE public.appointment (id BIGSERIAL NOT NULL, version BIGINT, customer_id BIGINT, duration BYTEA, note TEXT, personal_available BOOLEAN DEFAULT 0, personal_booked BOOLEAN DEFAULT 0, provider_id BIGINT, start_time BYTEA, url VARCHAR(255), CONSTRAINT "appointmentPK" PRIMARY KEY (id))]
    at liquibase.executor.jvm.JdbcExecutor$ExecuteStatementCallback.doInStatement(JdbcExecutor.java:316)

...

Caused by: org.postgresql.util.PSQLException: ERROR: relation "appointment" already exists

我将不胜感激任何想法，为什么它不起作用。

谢谢格雷格·佩特金。设置dbcreate进行验证确实可以帮助我解决此错误。

Answer 1

问题在于您的dbCreate子句以及行为的非常不便的更改，导致无效的dbCreate值被忽略。如果您不希望Hibernate弄乱数据库并干扰数据库迁移，请使用dbCreate: validate。

插件可以为Grails应用程序提供值，因此它们可以提供合理的默认值，并且可以从头开始工作:首先一个接一个地插入插件，最后application.yml可以覆盖它们设置的任何内容。为了便于开发和测试，插件也是独立的Grails应用程序，因此其中许多插件都具有dbCreate设置。

发生的不便之处在于，现在无效的dbCreate选项将被覆盖，然后覆盖由随机选择的最新插件留下的值，从而有可能有助于配置(该插件也可以使用create-drop，这可能是即使在开发环境中也非常不方便-实际上，较新的Grails版本将忽略插件中的dbCreate设置，因为当前行为是如此危险)。

因此，当数据库迁移运行时，Hibernate已经使用update或create-drop设置来创建表，因此数据库迁移失败。将值配置为validate应该为覆盖插件设置提供了有效的替代。