我无法创建EclipseLink将创建的JPA模型类 关注PostgreSQL DDL：
CREATE TABLE array_example (
id serial not null,
params text[] not null
);
据我所知，PostgreSQL的数组类型不是SQL标准，因此不受JPA标准的约束。 EclipseLink似乎对非标准扩展提供某种支持。到目前为止，我提出了以下课程：
....
import org.eclipse.persistence.annotations.Array;
import org.eclipse.persistence.annotations.Struct;
@Entity
@Table(name = "array_example")
@Struct(name = "params") // Else: [EclipseLink-157] "Normal descriptors do not support non-relational extensions."
@XmlRootElement
public class ArrayExamplePostgres implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "id")
private int id;
@NotNull
@Array(databaseType = "TEXT[]") // Needs @Struct on class!
@Column(name = "params")
private List<String> params;
....
运行我的测试脚本时出现以下错误：
Mai 12, 2014 1:35:13 AM org.eclipse.persistence.default
WARNING: The default table generator currently only supports generating default table schema from a relational project.
Mai 12, 2014 1:35:13 AM org.eclipse.persistence.session.file:/srv/home/james/workspace/java_test/java_test_ee6_jpa/target/classes/_postgresJavaTestJpaPU
WARNING:
Local Exception Stack:
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: org.postgresql.util.PSQLException: Unable to find server array type for provided name TEXT[].
Error Code: 0
Query: InsertObjectQuery(de.lathspell.java_test_ee6_jpa.model.ArrayExamplePostgres@3c77af84)
at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:326)
at org.eclipse.persistence.mappings.structures.ObjectRelationalDataTypeDescriptor.buildFieldValueFromDirectValues(ObjectRelationalDataTypeDescriptor.java:102)
at org.eclipse.persistence.mappings.foundation.AbstractCompositeDirectCollectionMapping.writeFromObjectIntoRow(AbstractCompositeDirectCollectionMapping.java:617)
at org.eclipse.persistence.internal.descriptors.ObjectBuilder.buildRow(ObjectBuilder.java:1394)
at org.eclipse.persistence.internal.descriptors.ObjectBuilder.buildRow(ObjectBuilder.java:1382)
at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.insertObjectForWrite(DatabaseQueryMechanism.java:450)
at org.eclipse.persistence.queries.InsertObjectQuery.executeCommit(InsertObjectQuery.java:80)
at org.eclipse.persistence.queries.InsertObjectQuery.executeCommitWithChangeSet(InsertObjectQuery.java:90)
at org.eclipse.persistence.internal.queries.DatabaseQueryMechanism.executeWriteWithChangeSet(DatabaseQueryMechanism.java:300)
at org.eclipse.persistence.queries.WriteObjectQuery.executeDatabaseQuery(WriteObjectQuery.java:58)
at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:899)
at org.eclipse.persistence.queries.DatabaseQuery.executeInUnitOfWork(DatabaseQuery.java:798)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWorkObjectLevelModifyQuery(ObjectLevelModifyQuery.java:108)
at org.eclipse.persistence.queries.ObjectLevelModifyQuery.executeInUnitOfWork(ObjectLevelModifyQuery.java:85)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2894)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1797)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1779)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1730)
at org.eclipse.persistence.internal.sessions.CommitManager.commitNewObjectsForClassWithChangeSet(CommitManager.java:226)
at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:125)
at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:4200)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1439)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithPreBuiltChangeSet(UnitOfWorkImpl.java:1585)
at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.writeChanges(RepeatableWriteUnitOfWork.java:452)
at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:846)
at de.lathspell.java_test_ee6_jpa.model.ArrayExamplePostgresTest.testArrays(ArrayExamplePostgresTest.java:31)
...
PostgreSQL日志文件包含两个可疑的SELECT（在_text后返回1009，然后是typedelim = NULL），因为丢失了表，它在失败之前不久：
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] LOG: execute <unnamed>: SELECT oid FROM pg_catalog.pg_type WHERE typname = $1
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] DETAIL: parameters: $1 = '_text
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] LOG: execute <unnamed>: SELECT e.typdelim FROM pg_catalog.pg_type t, pg_catalog.pg_type e WHERE t.oid = $1 and t.typelem = e.oid
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] DETAIL: parameters: $1 = '1009'
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] LOG: execute S_1: BEGIN
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] ERROR: relation "array_example" does not exist at character 13
2014-05-12 01:34:32 CEST postgres@java_test_ee6_jpa [17555] STATEMENT: INSERT INTO array_example (params) VALUES ($1)
持久性配置的相关部分是：
<persistence-unit name="postgresJavaTestJpaPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>de.lathspell.java_test_ee6_jpa.model.ArrayExamplePostgres</class>
...
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:postgresql:java_test_ee6_jpa"/>
<property name="javax.persistence.jdbc.user" value="postgres"/>
<property name="javax.persistence.jdbc.password" value="secret"/>
<property name="eclipselink.ddl-generation.output-mode" value="both"/>
<property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
<property name="eclipselink.drop-ddl-jdbc-file-name" value="src/main/sql/eclipselink-postgres-drop.sql"/>
<property name="eclipselink.create-ddl-jdbc-file-name" value="src/main/sql/eclipselink-postgres-create.sql"/>
<property name="eclipselink.jdbc.native-sql" value="true"/>
</properties>
</persistence-unit>
修改
使用@Array时（databaseType =＆＃34; TEXT＆＃34;）我得到一个SQL查询但没有生成架构：
2014-05-12 23:03:08 CEST postgres@java_test_ee7_jpa [4183] LOG: execute <unnamed>: SELECT pg_type.oid FROM pg_catalog.pg_type LEFT JOIN (select ns.oid as nspoid, ns.nspname, r.r from pg_namespace as ns join ( select s.r, (current_schemas(false))[s.r] as nspname from generate_series(1, array_upper(current_schemas(false), 1)) as s(r) ) as r using ( nspname ) ) as sp ON sp.nspoid = typnamespace WHERE typname = $1 ORDER BY sp.r, pg_type.oid DESC LIMIT 1
2014-05-12 23:03:08 CEST postgres@java_test_ee7_jpa [4183] DETAIL: parameters: $1 = '_TEXT'
-> 0 rows
使用@Array时（databaseType =＆＃34; text []＆＃34;我得到一个SQL查询但没有生成架构：
2014-05-12 23:12:21 CEST postgres@java_test_ee7_jpa [4435] LOG: execute <unnamed>: SELECT pg_type.oid FROM pg_catalog.pg_type LEFT JOIN (select ns.oid as nspoid, ns.nspname, r.r from pg_namespace as ns join ( select s.r, (current_schemas(false))[s.r] as nspname from generate_series(1, array_upper(current_schemas(false), 1)) as s(r) ) as r using ( nspname ) ) as sp ON sp.nspoid = typnamespace WHERE typname = $1 ORDER BY sp.r, pg_type.oid DESC LIMIT 1
2014-05-12 23:12:21 CEST postgres@java_test_ee7_jpa [4435] DETAIL: parameters: $1 = '_text[]'
-> 0 rows
使用@Array时（databaseType =＆＃34; text＆＃34;我得到两个实际产生结果的SQL查询，但仍然没有创建表，也不是EclipseLink创建的schema.sql：
2014-05-12 23:04:46 CEST postgres@java_test_ee7_jpa [4266] LOG: execute <unnamed>: SELECT pg_type.oid FROM pg_catalog.pg_type LEFT JOIN (select ns.oid as nspoid, ns.nspname, r.r from pg_namespace as ns join ( select s.r, (current_schemas(false))[s.r] as nspname from generate_series(1, array_upper(current_schemas(false), 1)) as s(r) ) as r using ( nspname ) ) as sp ON sp.nspoid = typnamespace WHERE typname = $1 ORDER BY sp.r, pg_type.oid DESC LIMIT 1
2014-05-12 23:04:46 CEST postgres@java_test_ee7_jpa [4266] DETAIL: parameters: $1 = '_text'
--> 1009
2014-05-12 23:04:46 CEST postgres@java_test_ee7_jpa [4266] LOG: execute <unnamed>: SELECT e.typdelim FROM pg_catalog.pg_type t, pg_catalog.pg_type e WHERE t.oid = $1 and t.typelem = e.oid
2014-05-12 23:04:46 CEST postgres@java_test_ee7_jpa [4266] DETAIL: parameters: $1 = '1009'
--> ','
在最后一个示例中，将打印一个新警告。如果我从persistence.xml中删除ArrayExample模型类，它就会消失，因此它似乎相关：
org.eclipse.persistence.default
WARNING: The default table generator currently only supports generating default table schema from a relational project.