Grails限制了桌子的创作 [英] grails limited table creation

问题描述

我想使用Grails功能在有限的基础上创建/更新数据库表。具体来说，我希望Grails管理一些表格，但不是全部。

I'd like to use the Grails feature for creating/updating database tables on a limited basis. Specifically, I'd like Grails to manage some tables, but not all.

是否有限制Grails管理的表的方法，或者它是全有还是全无命题？

Is there a way to limit the tables managed by Grails or is it an all or nothing proposition?

推荐答案

一般来说，Grails使用Hibernate的HBM2DDL功能完全没有。但是您可以使用自定义配置子类来拦截进程。下面是一个扩展GrailsAnnotationConfiguration并覆盖所有三种SQL生成方法的示例：

In general it's all or nothing since Grails uses Hibernate's HBM2DDL functionality. But you can intercept the process using a custom configuration subclass. Here's an example that extends GrailsAnnotationConfiguration and overrides all three SQL generation methods:

package com.yourcompany.yourapp;

import java.util.ArrayList;
import java.util.List;

import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsAnnotationConfiguration;
import org.hibernate.HibernateException;
import org.hibernate.dialect.Dialect;
import org.hibernate.tool.hbm2ddl.DatabaseMetadata;

public class MyConfiguration extends GrailsAnnotationConfiguration {

   private static final String[] IGNORE_NAMES = { "foo", "bar" };

   @Override
   public String[] generateDropSchemaScript(Dialect dialect) throws HibernateException {
      return prune(super.generateDropSchemaScript(dialect));
   }

   @Override
   public String[] generateSchemaCreationScript(Dialect dialect) throws HibernateException {
      return prune(super.generateSchemaCreationScript(dialect));
   }

   @Override
   public String[] generateSchemaUpdateScript(Dialect dialect, DatabaseMetadata databaseMetadata)
         throws HibernateException {
      return prune(super.generateSchemaUpdateScript(dialect, databaseMetadata));
   }

   private String[] prune(String[] script) {
      List<String> pruned = new ArrayList<String>();
      for (String command : script) {
         for (String ignoreName : IGNORE_NAMES) {
            if (!command.toLowerCase().contains(" table " + ignoreName + " ")) {
               pruned.add(command);
            }
         }
      }
      return pruned.toArray(new String[pruned.size()]);
   }
}

您不需要覆盖全部三个，例如您可以让创建过程，但删除更新。

You don't need to override all three, e.g. you could let creates go through but remove updates.

这得到注册在grails-app / conf / DataSource.groovy：

This gets registered in grails-app/conf/DataSource.groovy:

dataSource {
   pooled = true
   driverClassName = ...
   username = ...
   password = ...
   configClass = com.yourcompany.yourapp.MyConfiguration
}

请注意，类必须用Java编写，因为基类中私有方法的问题与Groovy添加到所有常规类的方法冲突。

Note that the class has to be written in Java because of an issue with private methods in the base class clashing with methods that Groovy adds to all groovy classes.

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