# No Dialect mapping for JDBC type 錯誤分析和解決方法
出現這個問題可能的原因：

1、資料庫欄位型別和JAVA型別不匹配。

2、Hibernate中錯誤地配置了資料庫方言。

## 解決方法：

**檢視java.sql.Types找到對應的型別。**

| 型別| 錯誤代碼 |
| -------- |--------|
|ARRAY | 2003
BIGINT | -5
BINARY | -2
BIT | -7
BLOB | 2004
BOOLEAN | 16
CHAR | 1
CLOB | 2005
DATALINK | 70
DATE | 91
DECIMAL | 3
DISTINCT | 2001
DOUBLE | 8
FLOAT | 6
INTEGER | 4
JAVA_OBJECT | 2000
LONGNVARCHAR | -16
LONGVARBINARY | -4
LONGVARCHAR | -1
NCHAR | -15
NCLOB | 2011
NULL | 0
NUMERIC | 2
NVARCHAR | -9
OTHER | 1111
REAL | 7
REF | 2006
ROWID | -8
SMALLINT | 5
SQLXML | 2009
STRUCT | 2002
TIME | 92
TIMESTAMP | 93
TINYINT | -6
VARBINARY | -3
VARCHAR | 12

**根據此表格可查出是資料庫中哪一種型別不匹配。
找到相對應缺少的再加進去即可**

import java.sql.Types;

import org.hibernate.dialect.SQLServerDialect;
import org.hibernate.type.StandardBasicTypes;

public class MySQLServerDialect extends SQLServerDialect{
	public MySQLServerDialect () {
        super();
        registerColumnType(Types.CHAR，"nchar(1)");
        registerColumnType(Types.LONGVARCHAR，"nvarchar(max)");
        registerColumnType(Types.VARCHAR，4000，"nvarchar($ l)");
        registerColumnType(Types.VARCHAR，"nvarchar(max)");
        registerColumnType(Types.CLOB，"nvarchar(max)");

        registerColumnType(Types.NCHAR，"nchar(1)");
        registerColumnType(Types.LONGNVARCHAR，"nvarchar(max)");
        registerColumnType(Types.NVARCHAR，4000，"nvarchar($ l)");
        registerColumnType(Types.NVARCHAR，"nvarchar(max)");
        registerColumnType(Types.NCLOB，"nvarchar(max)");

        registerHibernateType(1, "string");     
        registerHibernateType(-9, "string");     
        registerHibernateType(-15, "string");     
        registerHibernateType(-16, "string");     
        registerHibernateType(3, "double");  
          
        registerHibernateType(Types.CHAR, StandardBasicTypes.STRING.getName());     
        registerHibernateType(Types.NVARCHAR, StandardBasicTypes.STRING.getName());
        registerHibernateType(Types.NCHAR, StandardBasicTypes.STRING.getName()); 
        registerHibernateType(Types.LONGNVARCHAR, StandardBasicTypes.STRING.getName());     
        registerHibernateType(Types.DECIMAL, StandardBasicTypes.DOUBLE.getName());
        
        //registerHibernateType(Types.NCHAR，StandardBasicTypes.CHARACTER.getName());
        //registerHibernateType(Types.LONGNVARCHAR，StandardBasicTypes.TEXT.getName());
        //registerHibernateType(Types.NVARCHAR，StandardBasicTypes.STRING.getName());
        //registerHibernateType(Types.NCLOB，StandardBasicTypes.CLOB.getName());
    }
}

**然後修改Hibernate配置文件,將dialect指向自定義的dialect**

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"> 
   <property name="dataSource" ref="dataSource"/>
   <property name="packagesToScan" value="com.greatmap"/>
   <property name="hibernateProperties">
      <props>
          這裡指向自己設定的Dialect位置
         <prop key="hibernate.dialect">com.modules.sys.utils.MySQLServerDialect</prop>
         
         <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</prop>
         <prop key="net.sf.ehcache.configurationResourceName">${hibernate.ehcache.configFile}</prop>
         <prop key="hibernate.cache.use_second_level_cache">false</prop>
         <prop key="hibernate.cache.use_query_cache">false</prop>
         <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
         <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
         <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
      </props>
   </property>
</bean>