久久久WWW成人免费精品_ No Dialect mapping for JDBC type: 7

http://topic.csdn.net/u/20090304/20/d466a78e-2b2c-4623-8973-c998dda5612a.html

沒(méi)想到用SQLQUERY的時(shí)候可以有個(gè)簡(jiǎn)單的東西,就是

我看了錯誤信息有很多關(guān)于list的，網(wǎng)上幫你搜了一下，希望對你有所幫助。

createQuery與createSQLQuery兩者區別是：

前者用的hql語(yǔ)句進(jìn)行查詢(xún)，后者可以用sql語(yǔ)句查詢(xún)

前者以hibernate生成的Bean為對象裝入list返回

后者則是以對象數組進(jìn)行存儲

所以使用createSQLQuery有時(shí)候也想以hibernate生成的Bean為對象裝入list返回，就不是很方便

突然發(fā)現createSQLQuery有這樣一個(gè)方法可以直接轉換對象

Query query = session.createSQLQuery(sql).addEntity(XXX.class);

XXX 代表以hibernate生成的Bean的對象，也就是數據表映射出的Bean。

太牛了啊.我郁悶啊.

http://starrystarry-night.iteye.com/blog/566391

No Dialect mapping for JDBC type: 7
I got this error while I was working with hibernate and SQL Server. Following are the findings I came across. Hope this helps you too rectify this error.

Following questions are relevant to understand this clearly.

What is jdbc type 7?
java.sql.Type.REAL : It is a constant in the java programming language, that identifies SQL type REAL.
Value of this constant is 7. This is the above mentioned jdbc type 7.

What is dialect?
Dialect is the type of the database that hibernate is going to use. Following are the commonly used dialects. These are the subclasses of the org.hibernate.dialect.Dialect for specific databases.

org.hibernate.dialect.HSQLDialect
org.hibernate.dialect.Oracle9Dialect
org.hibernate.dialect.MySQLDialect
org.hibernate.dialect.SQLServerDialect
org.hibernate.dialect.FirebirdDialect
What cause this error to occur?
The database may contain a table with field of datatype real. Hibernate dialect SQLServerDialect doesnot understand this type. So we need to explicitly convert this real type to one that dialect can understand. One way to achieve this is to write a subclass of org.hibernate.dialect.SQLServerDialect.

package co.nr.javaalert.hibernate.dialect;
import java.sql.Types;
public class SubSQLServerDialect extends org.hibernate.dialect.SQLServerDialect{
public SQLServerDialectForBilling() {
super();
registerColumnType(Types.REAL,"number($p,$s)");
registerHibernateType(Types.REAL,"double");
}
}

registerColumnType() method register a type name for a given type code. This step register sql column data type NUMBER(precision,scale) to Types.REAL. Then register this Types.REAL with a data type that can understand hibernate. The recommended Java mapping for the sql REAL type is as a Java float.

Use this subclass instead of org.hibernate.dialect.SQLServerDialect in hibernate.cfg.xml.

Reference
SQL dialects reference/Data structure definition/Data types/Numeric types

原文:http://www.fengfly.com/plus/view-168177-1.html

Hibernate 數據庫連接及SQLDialect 錯誤: No Dialect mapping for JDBC type

時(shí)間:2010-01-22 14:19 點(diǎn)擊:1235次字體：[大中小]

Hibernate 不同數據庫的連接及SQL方言

<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>

<property name="connection.url">jdbc:mysql://localhost/dbname?characterEncoding=gb2312</property>

<property name="connection.username">root</property>

<property name="connection.password">root</property>


  
  <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
  <property name="connection.driver_class">net.sourceforge.jtds.jdbc.Driver</property>

<property name="connection.url">jdbc:jtds:sqlserver://localhost:1433;DatabaseName=dbname</property>

<property name="connection.username">sa</property>

<property name="connection.password"></property>

<property name="dialect">org.hibernate.dialect.OracleDialect</property>
  <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>

<property name="connection.url">jdbc:oracle:thin:@localhost:1521:dbname</property>

<property name="connection.username">test</property>

<property name="connection.password">test</property>

如果出現如下錯誤，則可能是Hibernate SQL方言 (hibernate.dialect)設置不正確。
Caused by: java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]'last_insert_id' 不是可以識別的函數名。

RDBMS	方言
DB2	`org.hibernate.dialect.DB2Dialect`
DB2 AS/400	`org.hibernate.dialect.DB2400Dialect`
DB2 OS390	`org.hibernate.dialect.DB2390Dialect`
PostgreSQL	`org.hibernate.dialect.PostgreSQLDialect`
MySQL	`org.hibernate.dialect.MySQLDialect`
MySQL with InnoDB	`org.hibernate.dialect.MySQLInnoDBDialect`
MySQL with MyISAM	`org.hibernate.dialect.MySQLMyISAMDialect`
Oracle (any version)	`org.hibernate.dialect.OracleDialect`
Oracle 9i/10g	`org.hibernate.dialect.Oracle9Dialect`
Sybase	`org.hibernate.dialect.SybaseDialect`
Sybase Anywhere	`org.hibernate.dialect.SybaseAnywhereDialect`
Microsoft SQL Server	`org.hibernate.dialect.SQLServerDialect`
SAP DB	`org.hibernate.dialect.SAPDBDialect`
Informix	`org.hibernate.dialect.InformixDialect`
HypersonicSQL	`org.hibernate.dialect.HSQLDialect`
Ingres	`org.hibernate.dialect.IngresDialect`
Progress	`org.hibernate.dialect.ProgressDialect`
Mckoi SQL	`org.hibernate.dialect.MckoiDialect`
Interbase	`org.hibernate.dialect.InterbaseDialect`
Pointbase	`org.hibernate.dialect.PointbaseDialect`
FrontBase	`org.hibernate.dialect.FrontbaseDialect`
Firebird	`org.hibernate.dialect.FirebirdDialect`

以上是轉載來(lái)的

///////////////////////////////////////////////////////////////////////////////////////////

有時(shí)候，hibernate用原生SQL 查詢(xún)，native SQL 的時(shí)候，會(huì )出現

org.hibernate.MappingException: No Dialect mapping for JDBC type: -1 ，-16，等等的錯誤

type 類(lèi)型代碼可以看 java.sql.Types 中的定義，看源碼就可以了

那是因為 Dialect 未定義，重寫(xiě)類(lèi)，把未定義的Dialect 注冊一下即可，

并且在 hibernate.cfg.xml中加入

Xml代碼

<property name="hibernate.dialect">
org.hibernate.dialect.OracleCustomDialect
</property>

Java代碼

import java.sql.Types;
import org.hibernate.Hibernate;
public class OracleCustomDialect extends org.hibernate.dialect.Oracle10gDialect {
public OracleCustomDialect() {
super();
registerHibernateType(Types.FLOAT, Hibernate.FLOAT.getName());
}
}

這是自己解決的折中辦法，最好還是遵循標準類(lèi)型

在hibernate中，Oracle9Dialect 方言定義有以下代碼：

Java代碼

public class Oracle9Dialect extends Dialect {
private static final Logger log = LoggerFactory.getLogger( Oracle9Dialect.class );
public Oracle9Dialect() {
super();
log.warn( "The Oracle9Dialect dialect has been deprecated; use either Oracle9iDialect or Oracle10gDialect instead" );
registerColumnType( Types.BIT, "number(1,0)" );
registerColumnType( Types.BIGINT, "number(19,0)" );
registerColumnType( Types.SMALLINT, "number(5,0)" );
registerColumnType( Types.TINYINT, "number(3,0)" );
registerColumnType( Types.INTEGER, "number(10,0)" );
registerColumnType( Types.CHAR, "char(1 char)" );
registerColumnType( Types.VARCHAR, 4000, "varchar2($l char)" );
registerColumnType( Types.VARCHAR, "long" );
registerColumnType( Types.FLOAT, "float" );
registerColumnType( Types.DOUBLE, "double precision" );
registerColumnType( Types.DATE, "date" );
registerColumnType( Types.TIME, "date" );
registerColumnType( Types.TIMESTAMP, "timestamp" );
registerColumnType( Types.VARBINARY, 2000, "raw($l)" );
registerColumnType( Types.VARBINARY, "long raw" );
registerColumnType( Types.NUMERIC, "number($p,$s)" );
registerColumnType( Types.DECIMAL, "number($p,$s)" );
registerColumnType( Types.BLOB, "blob" );
registerColumnType( Types.CLOB, "clob" );
……
……

而hibernate 3.3.2中帶的Oracle10gDialect方言代碼如下，是繼承了 Oracle9Dialect

Java代碼

public class Oracle10gDialect extends Oracle9iDialect {
public Oracle10gDialect() {
super();
}
public JoinFragment createOuterJoinFragment() {
return new ANSIJoinFragment();
}
}

同時(shí)，在public abstract class Dialect 類(lèi)中，定義了以下registerHibernateType，所有的數據庫類(lèi)型的Dialect都是 extends Dialect

Java代碼

protected Dialect() {
log.info( "Using dialect: " + this );
sqlFunctions.putAll( STANDARD_AGGREGATE_FUNCTIONS );
// standard sql92 functions (can be overridden by subclasses)
registerFunction( "substring", new SQLFunctionTemplate( Hibernate.STRING, "substring(?1, ?2, ?3)" ) );
registerFunction( "locate", new SQLFunctionTemplate( Hibernate.INTEGER, "locate(?1, ?2, ?3)" ) );
registerFunction( "trim", new SQLFunctionTemplate( Hibernate.STRING, "trim(?1 ?2 ?3 ?4)" ) );
registerFunction( "length", new StandardSQLFunction( "length", Hibernate.INTEGER ) );
registerFunction( "bit_length", new StandardSQLFunction( "bit_length", Hibernate.INTEGER ) );
registerFunction( "coalesce", new StandardSQLFunction( "coalesce" ) );
registerFunction( "nullif", new StandardSQLFunction( "nullif" ) );
registerFunction( "abs", new StandardSQLFunction( "abs" ) );
registerFunction( "mod", new StandardSQLFunction( "mod", Hibernate.INTEGER) );
registerFunction( "sqrt", new StandardSQLFunction( "sqrt", Hibernate.DOUBLE) );
registerFunction( "upper", new StandardSQLFunction("upper") );
registerFunction( "lower", new StandardSQLFunction("lower") );
registerFunction( "cast", new CastFunction() );
registerFunction( "extract", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(?1 ?2 ?3)") );
//map second/minute/hour/day/month/year to ANSI extract(), override on subclasses
registerFunction( "second", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(second from ?1)") );
registerFunction( "minute", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(minute from ?1)") );
registerFunction( "hour", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(hour from ?1)") );
registerFunction( "day", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(day from ?1)") );
registerFunction( "month", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(month from ?1)") );
registerFunction( "year", new SQLFunctionTemplate(Hibernate.INTEGER, "extract(year from ?1)") );
registerFunction( "str", new SQLFunctionTemplate(Hibernate.STRING, "cast(?1 as char)") );
// register hibernate types for default use in scalar sqlquery type auto detection
registerHibernateType( Types.BIGINT, Hibernate.BIG_INTEGER.getName() );
registerHibernateType( Types.BINARY, Hibernate.BINARY.getName() );
registerHibernateType( Types.BIT, Hibernate.BOOLEAN.getName() );
registerHibernateType( Types.CHAR, Hibernate.CHARACTER.getName() );
registerHibernateType( Types.DATE, Hibernate.DATE.getName() );
registerHibernateType( Types.DOUBLE, Hibernate.DOUBLE.getName() );
registerHibernateType( Types.FLOAT, Hibernate.FLOAT.getName() );
registerHibernateType( Types.INTEGER, Hibernate.INTEGER.getName() );
registerHibernateType( Types.SMALLINT, Hibernate.SHORT.getName() );
registerHibernateType( Types.TINYINT, Hibernate.BYTE.getName() );
registerHibernateType( Types.TIME, Hibernate.TIME.getName() );
registerHibernateType( Types.TIMESTAMP, Hibernate.TIMESTAMP.getName() );
registerHibernateType( Types.VARCHAR, Hibernate.STRING.getName() );
registerHibernateType( Types.VARBINARY, Hibernate.BINARY.getName() );
registerHibernateType( Types.NUMERIC, Hibernate.BIG_DECIMAL.getName() );
registerHibernateType( Types.DECIMAL, Hibernate.BIG_DECIMAL.getName() );
registerHibernateType( Types.BLOB, Hibernate.BLOB.getName() );
registerHibernateType( Types.CLOB, Hibernate.CLOB.getName() );
registerHibernateType( Types.REAL, Hibernate.FLOAT.getName() );

如果有特殊類(lèi)型確實(shí)需要，只能自定義。

所以oracle的類(lèi)型定義最好遵循以上的 java.sql.Types，

在hibernate.cfg.xml中使用 org.hibernate.dialect.OracleCustomDialect

以防出現No Dialect mapping for JDBC type錯誤

其他的數據庫類(lèi)型，SQL SERVER DB2 MYSQL 等等，都可以查看 hibernate的相關(guān)源碼找出個(gè)所以然來(lái)

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Hibernate 數據庫連接及SQLDialect 錯誤: No Dialect mapping for JDBC type