问题
I am trying to run some Hibernate/JPA examples using an in-memory HSQL DB. The error message I get is the following:
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
The corresponding class is:
@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
}
The embeddable is:
@Embeddable
public class AnEmbeddable implements Serializable {
private String s;
public AnEmbeddable() { }
public String getS() {
return s;
}
public void setS(String s) {
this.s = s;
}
}
My 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>
I am on Hibernate 4.1.5.Final and HSQLDB 2.2.8.
Does anyone know what is causing this issue and how to solve it?
回答1:
You can ignore these error. Combination of create-drop and in-memory database produces these for every database object it tries to drop. Reason being that there is not any database objects to remove - DROP statements are executed against empty database.
Also with normal permanent database such a errors do come, because Hibernate does not figure out before executing DROP statements does added object exist in database or is it new.
回答2:
This solution worked for me, as opposed to the other solution that's given. Apparently mileages vary.
This was my exact error:
HHH000389: Unsuccessful: alter table ... drop constraint FK_g1uebn6mqk9qiaw45vnacmyo2 if exists
Table "..." not found; SQL statement: ...
This is my solution, overriding the H2 dialect:
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;
}
}
回答3:
The Solution @Sander provided above works for MYSQL too. Just extend MySQL5InnoDBDialect instead like below:
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;
}
}
Then in your datasource file change the following line:
dialect = org.hibernate.dialect.MySQL5InnoDBDialect
to
dialect = my.package.name.ImprovedMySQLDialect
回答4:
Just set dbCreate="update", and the errors go away immediately.
See: https://stackoverflow.com/a/31257468/715608
回答5:
The annoying error messages became more obnoxious stack traces at the start of every test using an in-memory database with HSQLDB and hbm2ddl.auto=create-drop.
The response to an HSQLDB bug report suggested the use of DROP TABLE ... CASCADE rather than DROP CONSTRAINT IF EXISTS. Unfortunately the HSQLDB syntax for drop table is DROP TABLE <table> [IF EXISTS] [RESTRICT | CASCADE]; Hibernate Dialect does not provide an easy mechanism for a Dialect to specify CASCADE following the final IF EXISTS clause. I wrote a bug for this limitation.
However, I was able to overcome the issue by creating a custom Dialect as follows:
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;
};
}
回答6:
We faced same issue while trying to create a simple login window in Spring. There were two tables user and role both with primary key id type of BIGINT. These we mapped (Many-to-Many) into another table user_roles with two columns user_id and role_id as foreign keys.
The problem was the role_id column in user_roles table, it was of int type and not compatible for the foreign key to role. When the type was modified to BIGINT errors were rectified.
来源：https://stackoverflow.com/questions/12054422/unsuccessful-alter-table-xxx-drop-constraint-yyy-in-hibernate-jpa-hsqldb-standa