org.hibernate.MappingException: No Dialect mapping for JDBC type: -4

傷城~ 2022-08-05 07:40 112阅读 0赞

Stacktraces
    
    org.hibernate.MappingException: No Dialect mapping for JDBC type: -4
        org.hibernate.dialect.TypeNames.get(TypeNames.java:56)
        org.hibernate.dialect.TypeNames.get(TypeNames.java:81)
        org.hibernate.dialect.Dialect.getHibernateTypeName(Dialect.java:370)
        org.hibernate.loader.custom.CustomLoader$Metadata.getHibernateType(CustomLoader.java:559)
        org.hibernate.loader.custom.CustomLoader$ScalarResultColumnProcessor.performDiscovery(CustomLoader.java:485)
        org.hibernate.loader.custom.CustomLoader.autoDiscoverTypes(CustomLoader.java:501)
        org.hibernate.loader.Loader.getResultSet(Loader.java:1796)
        org.hibernate.loader.Loader.doQuery(Loader.java:674)

**问题还原：**

数据库为MySQL,读取表中一个Blog类型字段

String hql ="select ID,IMG from test";
    Session session = getSession();
    list = session.createSQLQuery(hql).list();

**问题解决：**

这是由于mysql(BLOB或text)在hibernate中没有注册该类型

重写MySQL方言，新建一个类

import java.sql.Types;
    import org.hibernate.Hibernate;
    import org.hibernate.dialect.MySQLDialect;
    
    public class BlobMySQLDialect extends MySQLDialect{
    	public BlobMySQLDialect () {
            super();
            registerHibernateType(Types.LONGVARBINARY, Hibernate.BLOB.getName());
        }
    }

修改Hibernate配置文件

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>   
    修改为：  
    <property name="dialect">该类所在路径/BlobMySQLDialect</property>

作者：[itmyhome][]

[itmyhome]: http://blog.csdn.net/itmyhome1990