#1 Transaction Propagation Behavior
Required:Excute within a current tx, create a new one if none exists.
Supports: Excute within a current tx, execute without a tx if none exsits.
Mandatory: Excute within a current tx, throw an exception if none exists.
Requires New: Create a new tx and excute within the tx, suspend the current tx if one exists.
Not Supported: Excute without a tx, suspend the current tx if none exsits.
Never: Excute without a tx, throw an exception if a tx exsits.
#2 Transaction Isolation Level[1]
#2.1 Concurrent Problem
Dirty Reads: 鑴忚錛堣剰鏁版嵁鎸囧凡鏇存柊錛岃繕娌℃彁浜ょ殑鏁版嵁錛夈備簨鍔1璇誨彇鍒頒簨鍔2涓殑鑴忔暟鎹?/FONT>
Unrepeatable Reads: 涓嶅彲閲嶅璇匯備簨鍔1媯(gè)绱㈠埌鏌愯鍚庯紝浜嬪姟T2鏇存柊騫舵彁浜や簡(jiǎn)璇ヨ錛岃嫢浜嬪姟T2鍐嶆媯(gè)绱㈣琛岋紝鍒欎細(xì)鐪嬪埌涓嶄竴鏍風(fēng)殑緇撴灉銆?/FONT>
Phantom Reads: 铏氳銆備簨鍔1媯(gè)绱㈠埌絎﹀悎鏌愭潯浠剁殑琛岄泦鍚庯紝浜嬪姟T2鎻掑叆騫舵彁浜や簡(jiǎn)婊¤凍璇ユ潯浠剁殑鏂拌錛岃嫢浜嬪姟T2鍐嶆鎸夎鏉′歡媯(gè)绱紝鍒欎細(xì)鐪嬪埌浠ュ墠涓嶅瓨鍦ㄧ殑琛屸淧hantom鈥濄?/FONT>
#2.2 Isolation Level
+---------------+-------+------------------+-----------+
|Isolation Level|Phantom|Unrepeatable Reads|Dirty Reads|
+---------------+-------+------------------+-----------+
|Read Uncommited| Y | Y | Y |
+---------------+-------+------------------+-----------+
|Read Commited | Y | Y | N |
+---------------+-------+------------------+-----------+
|Repeatable Read| Y | N | N |
+---------------+-------+------------------+-----------+
|Serializable | N | N | N |
+---------------+-------+------------------+-----------+
#3 Timeout
#4 ReadOnly Transaction
鍙浜嬪姟淇濊瘉浜?jiǎn)澶氭潯鏌ヨSQL鐨勫湪浜嬪姟綰у埆鐨勮涓鑷存с侸DBC鍜屾暟鎹簱浼?xì)瀵瑰彧璇讳簨鍔″仛涓浜涗紭鍖栥?/FONT>
[1] C.J.Date, An Introduction to Database Systems 7th.
#0
涔﹀拰鏂囨。涓婂啓鐨勯兘涓嶆槸鐗規(guī)竻妤氱殑銆傝嚜宸辮涓嬫潵銆?/FONT>
#1 Using a PK association
#1.1 POJO with XDolclet annotation
public class Customer {
/**
* @return Returns the shoppingCart.
* @hibernate.many-to-one cascade="delete" column="shopping_cart_id"
* unique="true" foreign-key="FK_SHOPPING_CART__CUSTOMER"
*/
public ShoppingCart getShoppingCart() {
return shoppingCart;
}
}
public class ShoppingCart {
/**
* @return Returns the customer.
* @hibernate.one-to-one property-ref="shoppingCart"
*/
public Customer getCustomer() {
return customer;
}
}
property-ref="shoppingCart" 鍛婅瘔Hibernate ShoppingCart#customer鍜孋ustomer#shoppingCart鏄弽鍚戠殑鍏崇郴銆傛墍浠ibernate鐭ラ亾濡備綍浠嶴hoppingCart#getCustomer涓绱㈠埌鐩稿簲鐨刢ustomer瀵硅薄銆傚彇鍑烘煇涓狢ustomer瀵硅薄鏃訛紝Hibernate浼?xì)鐢熸垚DEBUG SQL:324 - 3涓殑SQL璇彞銆?/FONT>
#1.2 HBM
Customer.hbm.xml
<many-to-one
name="shoppingCart"
class="ShoppingCart"
cascade="delete"
outer-join="auto"
foreign-key="FK_SHOPPING_CART__CUSTOMER"
column="shopping_cart_id"
/>
ShoppingCart.hbm.xml
<one-to-one
name="customer"
class="Customer"
cascade="none"
outer-join="auto"
constrained="false"
property-ref="shoppingCart"
/>
#1.3 SCHEMA SQL
create table CUSTOMER (
ID bigint generated by default as identity (start with 1),
SHOPPING_CART_ID bigint,
primary key (ID)
)
create table SHOPPING_CART (
ID bigint generated by default as identity (start with 1)
primary key (ID)
)
alter table CUSTOMER
add constraint FK_SHOPPING_CART__CUSTOMER
foreign key (SHOPPING_CART_ID)
references SHOPPING_CART
#1.4 Query SQL
DEBUG SQL:324 - 1
select customer0_.ID as ID, customer0_.SHOPPING_CART_ID as SHOPPING2_3_, customer0_.USERNAME as USERNAME3_, customer0_.PWD as PWD3_
from CUSTOMER customer0_
where customer0_.USERNAME=? and customer0_.PWD=?
DEBUG SQL:324 - 2
select shoppingca0_.ID as ID0_, shoppingca0_.TOTAL as TOTAL8_0_
from SHOPPING_CART shoppingca0_
where shoppingca0_.ID=?
DEBUG SQL:324 - 3
select customer0_.ID as ID1_, customer0_.SHOPPING_CART_ID as SHOPPING2_3_1_, customer0_.USERNAME as USERNAME3_1_, customer0_.PWD as PWD3_1_, shoppingca1_.ID as ID0_, shoppingca1_.TOTAL as TOTAL8_0_
from
CUSTOMER customer0_
left outer join
SHOPPING_CART shoppingca1_
on customer0_.SHOPPING_CART_ID=shoppingca1_.ID
where customer0_.SHOPPING_CART_ID=?
#2 Using a FK association
#2.1 POJO with XDolclet annotation
public class Customer {
/**
* @return Returns the shoppingCart.
* @hibernate.one-to-one cascade="delete"
*/
public ShoppingCart getShoppingCart() {
return shoppingCart;
}
}
public class ShoppingCart {
/**
* @return Returns the id.
* @hibernate.id generator-class="foreign"
* @hibernate.generator-param name="property" value="customer"
*/
public Long getId() {
return id();
}
/**
* @return Returns the customer.
* @hibernate.one-to-one constrained="true" foreign-key="FK_CUSTOMER__SHOPPING_CART"
*/
public Customer getCustomer() {
return customer;
}
}
constrained="true" 鍛婅瘔Hibernate ShoppingCart鐨凱K榪樺簲璇ユ槸涓涓狥K錛岃繖涓狥K寮曠敤Customer鐨凱K銆傝繕闇瑕佸鍋氫竴鐐瑰伐浣滐紝澹版槑ShoppingCart鐨凱K鐢熸垚絳栫暐鏄痜oreign錛屽搴擲hoppingCart#customer銆傝繖鍜屼笂闈竴鍙ヨ瘽涓嶆槸涓涓剰鎬濆槢錛孎T~~
#2.2 HBM
Customer.hbm.xml
<one-to-one
name="shoppingCart"
class="ShoppingCart"
cascade="delete"
outer-join="auto"
constrained="false"
/>
ShoppingCart.hbm.xml
<id
name="id"
column="id"
type="java.lang.Long"
>
<generator class="foreign">
<param name="property">customer</param>
</generator>
</id>
<one-to-one
name="customer"
class="Customer"
cascade="none"
outer-join="auto"
constrained="true"
/>
#2.3 SCHEMA SQL
create table CUSTOMER (
ID bigint generated by default as identity (start with 1),
primary key (ID)
)
create table SHOPPING_CART (
ID bigint not null,
TOTAL integer,
primary key (ID)
)
alter table SHOPPING_CART
add constraint FK_CUSTOMER__SHOPPING_CART
foreign key (ID)
references CUSTOMER
#2.4 Query SQL
DEBUG SQL:324 -
select customer0_.ID as ID, customer0_.USERNAME as USERNAME3_, customer0_.PWD as PWD3_
from CUSTOMER customer0_
where customer0_.USERNAME=? and customer0_.PWD=?
DEBUG SQL:324 -
select shoppingca0_.ID as ID0_, shoppingca0_.TOTAL as TOTAL8_0_
from SHOPPING_CART shoppingca0_
where shoppingca0_.ID=?
榪欎釜鈥滅湡姝ｂ濈殑one-to-one鐨勫ソ澶勬槸灝戞潯鍏寵仈SQL璇彞錛岀湅鍒頒簡(jiǎn)鍚楋紵
Hello World!
Welcome to the ACM "Hello World" project. Everyone has seen the Hello World program used as a first exposure to a new language or environment. We are attempting to collect examples for as many languages and related programming environments (shells etc.) as possible.
Aproximate number of examples:204 <----wow~~~
This page has been accessed 33274 times.
Last updated: January 20, 2005
鐪嬬湅C鐨勶紝緇忓吀HelloWorld
#include <stdio.h>
main()
{
for(;;)
{
printf ("Hello World!\n");
}
}
榪欎篃鏄疕elloWolrd錛燂紒
a 1986 entry from Bruce Holloway:
#include "stdio.h"
#define e 3
#define g (e/e)
#define h ((g+e)/2)
#define f (e-g-h)
#define j (e*e-g)
#define k (j-h)
#define l(x) tab2[x]/h
#define m(n,a) ((n&(a))==(a))
long tab1[]={ 989L,5L,26L,0L,88319L,123L,0L,9367L };
int tab2[]={ 4,6,10,14,22,26,34,38,46,58,62,74,82,86 };
main(m1,s) char *s; {
int a,b,c,d,o[k],n=(int)s;
if(m1==1){ char b[2*j+f-g]; main(l(h+e)+h+e,b); printf(b); }
else switch(m1-=h){
case f:
a=(b=(c=(d=g)<<g)<'<g)<<g;
return(m(n,a|c)|m(n,b)|m(n,a|d)|m(n,c|d));
case h:
for(a=f;a
return(o[b-g]%n+k-h);
default:
if(m1-=e) main(m1-g+e+h,s+g); else *(s+g)=f;
for(*s=a=f;a<e;) *s=(*s<<e)|main(h+a++,(char *)m1);
}
}
鏇劇粡鏈鐭殑HelloWorld錛?A href="mailto:Jari.Arkko@lmf.eua.ericsson.se">Jari.Arkko@lmf.eua.ericsson.se錛?BR>jar.1.c
char*_="Hello world.\n";
ln -s /dev/tty jar.1.o
cc -c jar.1.c
鐜板湪鏈鐭殑HelloWorld 錛圝yrki Holopainen錛?BR>";main(){puts("Hello World!");}char*C=".c
char*_=__FILE__;
榪欐牱鐨勫叓鍗︾倰浣滆創(chuàng)涔熻兘鍦╦ava.csdn.net涓婄疆欏訛紝鐪熸槸鏃犺浜?jiǎn)~鎴戝彧鎯沖csdn璇達(dá)細(xì)鈥滀綘澶樊浜?jiǎn)锛佲?BR>銆婄▼搴忓憳銆嬫瘡鏈熼兘浼?xì)涔板Q屾槸鍥犱負(fù)鎴戞病鐨勯夋嫨銆備綔涓轟竴鏈妧鏈垔鐗╋紝銆婄▼搴忓憳銆嬩笉鏄繚鎸佷腑绔嬶紝鑰屾槸鎺烘潅浜?jiǎn)澶鐨勫晢涓氱珛鍦哄拰鍒╃泭銆傞珮姘村鉤鐨勬枃绔犱篃鏈夛紝浣嗚繙榪滀笉澶熴傝鏉傚織涓涓葷紪鎰熷徆娌℃湁瀵規(guī)墜錛岃銆奃DJ China銆嬧滃嚑涔庢槸涓涓悎鏍肩殑瀵規(guī)墜浜?jiǎn)鈥濄傝鐨勬瀬绔拰鍒昏杽涓鐐癸紝銆奃DJ銆嬫槸杞歡寮鍙戠殑瀛︽湳鍒婄墿錛宑sdn銆併婄▼搴忓憳銆嬪彧鑳界畻鏄▼搴忓憳鐨勫ū涔愭柊闂繪潅蹇椼?/P>
榪欐槸涓涓講鍚嶁滃懆鏄熸槦鈥濈殑鍚屽瀵瑰師鏂囩殑璇勮銆?BR>鍛ㄦ槦鏄?鍙戣〃浜?005-06-16 5:01 PM
鈥滃緢鏄庢樉錛孋++鐨勭紪璇戝櫒涓嶅java鐨凧IT鍜孒otSpot緙栬瘧鍣紝鍥犱負(fù)JIT鍜孒otSpot緙栬瘧鍣ㄨ兘閽堝CPU鎸囦護(hù)闆嗚繘琛屼漢浼樺寲銆佽兘鍦ㄨ繍琛屾椂鏍規(guī)嵁浣跨敤棰戠巼瀵筸ethod榪涜鍐呰仈鍜屼紭鍖栥傝孋++鐨勯潤(rùn)鎬佺紪璇戝櫒姘歌繙涔熷仛涓嶅埌榪欎簺鈥?
--- 鏃犵煡浜?jiǎn)鍚уQ岀幇瀛樹(shù)簬涓栫殑C++緙栬瘧鍣紝鏃犺鏄疺C++錛岃繕鏄疘ntel C++錛岃繕鏄痝++錛岄兘鑳介拡瀵圭壒瀹欳PU榪涜浼樺寲錛涜孞ava鐨勬墍璋撳姩鎬佷紭鍖栧彧鏄仛浜?jiǎn)閮ㄥ垎锛堜笉鏄叏閮ㄥQ塁++闈?rùn)鎬佷紭鍖栫殑宸ヤ綔錛涗簨瀹炰笂錛岀湡姝ｇ殑鍔ㄦ佷紭鍖栦笉鏄換浣曚竴涓珮綰ц璦鎵鑳藉仛鍒扮殑錛孋++涓嶈兘錛孋涓嶈兘錛孞ava鏇翠笉鑳斤紝蹇呴』鍐呭祵姹囩紪鎵嶈兘鍋氬埌榪欎竴鐐廣?
鈥淛DK1.0鏃訛紝java鐨勯熷害鏄疌++鐨?0鍒?0鍒嗕箣涓銆傝屽埌浜?jiǎn)jdk1.4鏃訛紝java鐨勬ц兘鍒欐槸C++鐨勪笁鍒嗕箣涓鍒?鍊嶏紙閫氬父C++鏄痡ava鐨?.2鍊嶅埌1.5鍊嶏級(jí)銆傚彲鎯滆繖鍒嗘姤鍛婃病鏈塲dk1.4浠ュ悗鐨勬暟鎹紝鑰屽悗闈㈢殑鎶ュ憡鎴戜滑灝嗙湅鍒板湪jdk1.4.2鏃訛紝java鎬ц兘鍏ㄩ潰瓚呰繃C++銆傗?
--- 鏈変釜10宀佺殑灝忓瀛愬濂?0姣嶄翰璇達(dá)細(xì)鈥?騫村墠鎴戠殑騫撮緞鏄Τ鐨?/21錛屾垜鐜板湪鐨勫勾榫勬槸濡崇殑1/3錛岄殢鐫榪欑瓚嬪娍鐨勫彂灞曪紝鍦ㄦ湭鏉ユ垜鐨勫勾榫勫氨鍙互瓚呰繃濡熾傗?
Java鐨勯熷害涔熻鍙互鎺ヨ繎C++錛屼絾姘歌繙涓嶅彲鑳借揪鍒癈++涓鏍峰揩錛屾洿涓嶅彲鑳借秴榪嘋++錛屽洜涓鴻В閲婄▼搴忓繀欏昏姹傚師鐢熺▼搴忔潵瑙ｉ噴鎵ц錛屾墍浠ユ案榪滆揪涓嶅埌涓鏍風(fēng)殑閫熷害銆?
鈥淛ava鍐欑殑鏁版嵁搴撶殑鎬ц兘鏄疌++鍐欑殑鏁版嵁搴撴ц兘鐨勮繎600鍊嶏紒鈥?
--- 澶╂柟澶滆礙錛屽鏋滅湡鐨勮繖鏍鳳紝MS SQL涓轟粈涔堜笉鐢↗ava鏉ョ紪鍐欙紝Oracle涓轟粈涔堜笉鐢↗ava鏉ョ紪鍐欙紝MySQL涓轟粈涔堜笉鐢↗ava鏉ョ紪鍐欙紵
鈥滀集鍏嬪埄澶у鍜孡awrence浼厠鍒╁浗瀹跺疄楠屽鐨勪竴浠芥姤鍛婅瘉鏄庯細(xì)IBM鐨凧DK姣擥CC鏇村揩鈥?
--- 浼厠鍒╁ぇ瀛︾湡鐨勬湁榪欎釜鎶ュ憡鍚楋紵鐪熸槸鐜鋒薄浼厠鍒╃殑濞佸悕錛屾妸JDK鍜孏CC鏀懼湪涓璧鋒瘮錛屽鍚屾妸鈥滈暱搴︹濆拰鈥滈噸閲忊濊繖涓ょ涓嶅悓鎬ц川鐨勪笢瑗挎斁鍦ㄤ竴璧鋒瘮銆?
鈥滅敤綰痡ava鍐欑殑JDK搴曞眰瑕佹瘮鐢–++鍐橨DK搴曞眰瑕佸揩鈥?
--- 鏅曪紝鈥滅函java鍐欑殑JDK鈥濓紝鏁欎綘Java鐨勮佸笀琚綘姘旇煩妤間簡(jiǎn)銆?/P>