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No Dialect mapping for JDBC type–4 hibernate查询MySQL中longBlob数据

MySQL数据库中的类型为longBlob

实体类定义为:byte[] 类型

映射文件配置为:type="org.springframework.orm.hibernate3.support.BlobByteArrayType

 

异常信息:

1 org.hibernate.MappingException: No Dialect mapping for JDBC type: -42     at org.hibernate.dialect.TypeNames.get(TypeNames.java:56)3     at org.hibernate.dialect.TypeNames.get(TypeNames.java:81)4     at org.hibernate.dialect.Dialect.getHibernateTypeName(Dialect.java:370)5     at org.hibernate.loader.custom.CustomLoader$Metadata.getHibernateType(CustomLoader.java:559)

解决办法:

 1、添加注册类:

 1 package com.prochanges.framework.utils; 2  3 import java.sql.Types; 4  5 import org.hibernate.Hibernate; 6 import org.hibernate.dialect.MySQL5Dialect; 7  8 public class BlobMySQLDialect extends MySQL5Dialect { 9     public BlobMySQLDialect() {10         super();11         registerHibernateType(Types.LONGVARBINARY, Hibernate.BLOB.getName());// 注册blob,Types.LONGVARBINARY的值就是-412     }13 }

2、修改配置文件中数据库的hibernate.dialec属性的值,即为刚写的注册类:

 <prop key="hibernate.dialect">com.prochanges.framework.utils.BlobMySQLDialect</prop>

 

No Dialect mapping for JDBC type–4 hibernate查询MySQL中longBlob数据