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摘要: As per the documentation on MySQL I moved the storage of passwords from using Password() to using MD5(). I read a number of places that stated that this was a method that couldn't be reversed and it was far more secure than the previous method. I was feeling confident that life was about to get a little more secure. While going through my daily RSS feeds and mailing lists for SpikeSource, I happenned upon a thread about someone discussing how easy it was to break MD5 hashes. It was a simple matt
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摘要: 1.如果存在就更新，不存在就插入用一個語句實;
2.分頁算法;
3.抽取/刪除重復(fù)記錄;
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摘要: Hibernate中支持3種形式實現(xiàn)繼承關(guān)系：
1. Table per concrete class 表與子類之間獨(dú)立一對一關(guān)系
2. Table per subclass 每個子類對應(yīng)一張子表，并與主類共享主表
3. Table per class hierarchy 表與類一對多關(guān)系
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