针对guzz的表分切与批量增加的应用
guzz的表切分功能,数据库表是需要提前建好的。
guzz对于单个记录的插入操作可以在插入之前设置 tableConditon.
例如:
WriteTranSession session=trm.openRWTran(true);
int userNo=1;
int courseNo=2;
try{
for(int i=0,j=100;i<j;i++)
{
userNo=i%4+1;
courseNo=courseNo%8+1;
Study study=new Study( userNo, courseNo);
Guzz.setTableCondition(study.getUserNo()) ;
session.insert(study) ;
System.out.println(study.getNo());//可以得到记录号
}
}finally{
session.close();
}
对于批量插入操作时不可以在每次insert的前一步设置 tableConditon.,
例如:
WriteTranSession session=trm.openRWTran(false);
int userNo=1;
int courseNo=2;
try{
ObjectBatcher batcher =session.createObjectBatcher();
Study study=new Study( userNo, courseNo);
for(int i=0,j=100;i<j;i++)
{
userNo=i%4+1;
courseNo=courseNo%8+1;
study=new Study( userNo, courseNo);
batcher.setTableCondition(study.getUserNo());//这里会报错的
batcher.insert(study) ;
System.out.println(study.getNo());
}
batcher.executeBatch();
session.commit();
}finally{
session.close();
}
我们可以改变成分批的批量处理的结果是:
WriteTranSession session=trm.openRWTran(false);
int userNo=1;
int courseNo=2;
try{
ObjectBatcher batcher1 =session.createObjectBatcher();
ObjectBatcher batcher2 =session.createObjectBatcher();
ObjectBatcher batcher3 =session.createObjectBatcher();
ObjectBatcher batcher4 =session.createObjectBatcher();
batcher1.setTableCondition(1);
batcher2.setTableCondition(2);
batcher3.setTableCondition(3);
batcher4.setTableCondition(4);
Study study=null;
for(int i=0,j=100;i<j;i++)
{
userNo=i%4+1;
courseNo=courseNo%8+1;
study=new Study( userNo, courseNo);
//batcher.setTableCondition(study.getUserNo());
switch(userNo)
{
case 1:
batcher1.insert(study);
break;
case 2:
batcher2.insert(study);
break;
case 3:
batcher3.insert(study);
break;
case 4 :
batcher4.insert(study);
break;
}
}
int s1[]=batcher1.executeBatch();
int s2[]=batcher2.executeBatch();
int s3[]=batcher3.executeBatch();
int s4[]=batcher4.executeBatch();
//s1、s2、s3、s4的元素值都是1
session.commit();
}finally{
session.close();
}
附录:
配置文件:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE guzz-mapping PUBLIC "-//GUZZ//GUZZ MAPPING DTD//EN" "http://www.guzz.org/dtd/guzz-mapping.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="com.uidd.messageBoard.pojo.Study" table="t_study_" shadow="com.sjdd.messageBoard.pojo.StudyShadouView">
<id name="no" type="int">
<generator class="identity" />
</id>
<property name="userNo" type="int" column="userNo" />
<property name="courseNo" type="int" column="courseNo" />
</class>
</hibernate-mapping>
分表的规则
package com.uidd.messageBoard.pojo;
import org.guzz.exception.GuzzException;
import org.guzz.orm.AbstractShadowTableView;
public class StudyShadouView extends AbstractShadowTableView {
public String toTableName(Object tableCondition) {
// TODO Auto-generated method stub
if(tableCondition == null){ //强制要求必须设置表分切条件,避免编程时疏忽。
throw new GuzzException("null table conditon is not allowed.") ;
}
int userNo = (Integer) tableCondition ;
//如果用户ID为偶数,记入TB_COMMENT1, 否则写入TB_COMMENT2
int i = userNo % 3 + 1 ;
return super.getConfiguredTableName() + i;
}
}
创建表的SQL
create table t_study_1
(
no INT AUTO_INCREMENT NOT NULL PRIMARY KEY,
userNo INT NOT NULL,
courseNo int NOT NULL
);
create table t_study_2
(
no INT AUTO_INCREMENT NOT NULL PRIMARY KEY,
userNo INT NOT NULL,
courseNo int NOT NULL
);
create table t_study_3
(
no INT AUTO_INCREMENT NOT NULL PRIMARY KEY,
userNo INT NOT NULL,
courseNo int NOT NULL
);
package com.uidd.messageBoard.pojo;
public class Study implements java.io.Serializable {
private int no;
private int userNo;
private int courseNo;
public int getNo() {
return no;
}
public void setNo(int no) {
this.no = no;
}
public int getUserNo() {
return userNo;
}
public void setUserNo(int userNo) {
this.userNo = userNo;
}
public int getCourseNo() {
return courseNo;
}
public void setCourseNo(int courseNo) {
this.courseNo = courseNo;
}
public Study() {
super();
// TODO Auto-generated constructor stub
}
public Study(int no, int userNo, int courseNo) {
super();
this.no = no;
this.userNo = userNo;
this.courseNo = courseNo;
}
public Study(int userNo, int courseNo) {
super();
this.userNo = userNo;
this.courseNo = courseNo;
}
}