[英]Unsuccessful: alter table XXX drop constraint YYY in Hibernate/JPA/HSQLDB standalone
我正在尝试使用内存中的HSQL DB运行一些Hibernate / JPA示例。 我收到的错误消息如下:
13:54:21,427 ERROR SchemaExport:425 - HHH000389: Unsuccessful: alter table ReferringItem_map drop constraint FK5D4A98E0361647B8
13:54:21,427 ERROR SchemaExport:426 - user lacks privilege or object not found: PUBLIC.REFERRINGITEM_MAP
13:54:21,427 ERROR SchemaExport:425 - HHH000389: Unsuccessful: alter table ReferringItem_myCollection drop constraint FK75BA3266361647B8
13:54:21,427 ERROR SchemaExport:426 - user lacks privilege or object not found: PUBLIC.REFERRINGITEM_MYCOLLECTION
13:54:21,428 ERROR SchemaExport:425 - HHH000389: Unsuccessful: alter table ReferringItem_myList drop constraint FK6D37AA66361647B8
13:54:21,428 ERROR SchemaExport:426 - user lacks privilege or object not found: PUBLIC.REFERRINGITEM_MYLIST
13:54:21,428 ERROR SchemaExport:425 - HHH000389: Unsuccessful: alter table ReferringItem_mySet drop constraint FK3512699A361647B8
13:54:21,429 ERROR SchemaExport:426 - user lacks privilege or object not found: PUBLIC.REFERRINGITEM_MYSET
对应的类是:
@Entity
public class ReferringItem implements Serializable {
@Id
private long id;
@ElementCollection
private Collection<AnEmbeddable> myCollection
= new ArrayList<AnEmbeddable>();
@ElementCollection(fetch=FetchType.EAGER)
private Set<Long> mySet = new HashSet<Long>();
@ElementCollection(targetClass=String.class)
private List myList = new ArrayList();
@ElementCollection
private Map<String,AnEmbeddable> map
= new HashMap<String,AnEmbeddable>();
public ReferringItem() { }
// Setters & Getters
}
可嵌入的是:
@Embeddable
public class AnEmbeddable implements Serializable {
private String s;
public AnEmbeddable() { }
public String getS() {
return s;
}
public void setS(String s) {
this.s = s;
}
}
我的persistence.xml
:
<persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0">
<persistence-unit name="JPA" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.jverstry.jpa.AuthorizedTypes.AuthorizedTypes</class>
<class>com.jverstry.jpa.AuthorizedTypes.OtherEntity</class>
<class>com.jverstry.jpa.AuthorizedTypes.SomeEmbeddable</class>
<properties>
<property name="javax.persistence.jdbc.driver" value="org.hsqldb.jdbcDriver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:hsqldb:mem:testdb"/>
<property name="javax.persistence.jdbc.user" value="sa"/>
<property name="javax.persistence.jdbc.password" value=""/>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
<property name="hibernate.hbm2ddl.auto" value="create-drop"/>
</properties>
</persistence-unit>
</persistence>
我在Hibernate 4.1.5.Final
和HSQLDB 2.2.8
。
有谁知道导致此问题的原因以及如何解决?
您可以忽略这些错误。 create-drop
和empty(内存中的情况总是如此)的组合会为它尝试删除的每个数据库对象生成这些。 原因是没有要删除的任何数据库对象-针对空数据库执行DROP语句。
同样,对于普通的永久数据库,也会出现这样的错误,因为Hibernate在执行DROP语句之前并不会确定数据库中是否存在添加的对象或者它是新对象。
与给定的其他解决方案相反,该解决方案对我有用。 显然,里程数有所不同。
这是我的确切错误:
HHH000389: Unsuccessful: alter table ... drop constraint FK_g1uebn6mqk9qiaw45vnacmyo2 if exists
Table "..." not found; SQL statement: ...
这是我的解决方案,覆盖了H2方言:
package com.totaalsoftware.incidentmanager;
import org.hibernate.dialect.H2Dialect;
/**
* Workaround.
*
* @see https://hibernate.atlassian.net/browse/hhh-7002
*
*/
public class ImprovedH2Dialect extends H2Dialect {
@Override
public String getDropSequenceString(String sequenceName) {
// Adding the "if exists" clause to avoid warnings
return "drop sequence if exists " + sequenceName;
}
@Override
public boolean dropConstraints() {
// We don't need to drop constraints before dropping tables, that just
// leads to error messages about missing tables when we don't have a
// schema in the database
return false;
}
}
上面提供的解决方案@Sander也适用于MYSQL。 只需如下扩展MySQL5InnoDBDialect即可:
import org.hibernate.dialect.MySQL5InnoDBDialect;
public class ImprovedMySQLDialect extends MySQL5InnoDBDialect {
@Override
public String getDropSequenceString(String sequenceName) {
// Adding the "if exists" clause to avoid warnings
return "drop sequence if exists " + sequenceName;
}
@Override
public boolean dropConstraints() {
// We don't need to drop constraints before dropping tables, that just leads to error
// messages about missing tables when we don't have a schema in the database
return false;
}
}
然后在数据源文件中更改以下行:
dialect = org.hibernate.dialect.MySQL5InnoDBDialect
至
dialect = my.package.name.ImprovedMySQLDialect
只需设置dbCreate="update"
,错误就会立即消失。
使用带有HSQLDB和hbm2ddl.auto = create-drop的内存数据库,在每次测试开始时,令人讨厌的错误消息都变得更加令人讨厌。
对HSQLDB错误报告的响应建议使用DROP TABLE ... CASCADE而不是DROP CONSTRAINT IF EXISTS。 不幸的是,删除表的HSQLDB语法是DROP TABLE <table> [IF EXISTS] [RESTRICT | CASCADE];
DROP TABLE <table> [IF EXISTS] [RESTRICT | CASCADE];
Hibernate方言没有提供一种简单的机制来让方言在最终的IF EXISTS子句之后指定CASCADE。 我为此限制编写了一个错误 。
但是,我可以通过如下创建自定义方言来解决此问题:
public class HsqlDialectReplacement extends HSQLDialect {
@Override
public String getDropTableString( String tableName ) {
// Append CASCADE to formatted DROP TABLE string
final String superDrop = super.getDropTableString( tableName );
return superDrop + " cascade";
}
@Override
public boolean dropConstraints() {
// Do not explicitly drop constraints, use DROP TABLE ... CASCADE
return false;
}
@Override
public Exporter<Table> getTableExporter() {
// Must override TableExporter because it also formulates DROP TABLE strings
synchronized( this ) {
if( null == overrideExporter ) {
overrideExporter = new HsqlExporter( super.getTableExporter() );
}
}
return overrideExporter;
}
private Exporter<Table> overrideExporter = null;
private static class HsqlExporter implements Exporter<Table> {
HsqlExporter( Exporter<Table> impl ) {
this.impl = impl;
}
@Override
public String[] getSqlCreateStrings( Table exportable, Metadata metadata ) {
return impl.getSqlCreateStrings( exportable, metadata );
}
@Override
public String[] getSqlDropStrings( Table exportable, Metadata metadata ) {
final String[] implDrop = impl.getSqlDropStrings( exportable, metadata );
final String[] dropStrings = new String[implDrop.length];
for( int i=0; i<implDrop.length; ++i ) {
dropStrings[i] = implDrop[i] + " cascade";
}
return dropStrings;
}
private final Exporter<Table> impl;
};
}
在Spring
尝试创建一个简单的登录窗口时,我们遇到了同样的问题。 有两个表user
和role
它们的主键id
类型均为BIGINT
。 我们将它们映射( Many-to-Many
)到另一个表user_roles
其中有两列user_id
和role_id
作为外键。
问题出在user_roles
表中的role_id
列,它是int
类型的,并且与role
的外键不兼容。 将类型修改为BIGINT
错误已得到纠正。
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