從MySql5中運(yùn)行本地腳本創(chuàng)建數(shù)據(jù)庫，當(dāng)插入中文字段時發(fā)生“data too long for column”錯誤。上網(wǎng)一查，發(fā)現(xiàn)多字節(jié)用戶大都碰到了這種情況。google搜索網(wǎng)上的解決方法大都是要將數(shù)據(jù)庫的編碼方式為GBK或UTF8，可我在安裝MySql時就選擇了UTF8格式。原來錯誤原因是本地的腳本文件不是UTF8編碼的，用記事本或UltraEdit將編碼轉(zhuǎn)為UTF8后問題解決。再次強(qiáng)調(diào)，JSP頁面，數(shù)據(jù)庫聯(lián)接接方式，數(shù)據(jù)庫創(chuàng)建，…，都須一致使用UTF8編碼！
BTW，MySql最近借著Web2.0的浪潮風(fēng)頭很勁啊，techn orati（好像這幾天被GFW filter了），flickr，del.icio.us等一批網(wǎng)站都是用了MySql。MySql還專門在首頁開了一大塊來炫耀。
Installed
JDK6
(Mustang) beta and
Eclipse3.2
. As
Sun promised
, Swing library, especially the?WindowsLookAndFeel feels much better. It’s hard to tell the difference between a Swing drawn window and a WINXP native window. Developing Java desktop applications is worth considering. Mattise, a free easy-to-use WYSIWYG Swing UI designer, is the only reason for many to use the tedious NetBeans. Recently,
Genuitec
provided Matisse4Eclipse, which is?an implementation of Matisse that integrates its functionality into MyEclipse Workbench to enable the easy creation of Swing applications with Eclipse. So the only reason to use NetBeans has gone.
去年7月決定考研后暫停了對Java技術(shù)的學(xué)習(xí)。錄研上后專心開發(fā)導(dǎo)師負(fù)責(zé)的項(xiàng)目，到4月份從深圳出差回來后又忙著做畢設(shè)。快一年的時間沒跟新這，幾乎都要abandon了。百度剛開放了百度空間的注冊，不過看起來不咋的。選國外的BSP會面臨隨時偉大的GFW過濾掉的后果。總的來說，BlogJava還是很適合post技術(shù)方面的東西，優(yōu)點(diǎn)是流量大，被google收錄快；缺點(diǎn)就是沒有trackback。前幾天下午跑到圖書館看了看上半年的程序員，新鮮玩意并不多。SOA，這個被預(yù)測為06年最熱點(diǎn)的技術(shù)，并沒有什么有趣的文章，或許這個名詞還是沒有個明確的含義和應(yīng)用。在學(xué)校里，IBM的SOA大賽倒是舉辦的風(fēng)風(fēng)火火。JavaEE5，JDK 6的發(fā)布還是給Java界帶來不少有趣又實(shí)用的新東東，比如annotation，persistence API和script supporting。得跟上技術(shù)前進(jìn)的步伐了，以后技術(shù)的筆記還是發(fā)這里，平日的雜想就寫在
我的MSN space上。
@title [筆記]事務(wù)處理
#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: 臟讀（臟數(shù)據(jù)指已更新，還沒提交的數(shù)據(jù)）。事務(wù)T1讀取到事務(wù)T2中的臟數(shù)據(jù)。
Unrepeatable Reads: 不可重復(fù)讀。事務(wù)T1檢索到某行后，事務(wù)T2更新并提交了該行，若事務(wù)T2再次檢索該行，則會看到不一樣的結(jié)果。
Phantom Reads: 虛讀。事務(wù)T1檢索到符合某條件的行集后，事務(wù)T2插入并提交了滿足該條件的新行，若事務(wù)T2再次按該條件檢索，則會看到以前不存在的行“Phantom”。
#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
只讀事務(wù)保證了多條查詢SQL的在事務(wù)級別的讀一致性。JDBC和數(shù)據(jù)庫會對只讀事務(wù)做一些優(yōu)化。
[1] C.J.Date, An Introduction to Database Systems 7th.