大约有 47,000 项符合查询结果（耗时：0.0914秒） [XML]
JPA EntityManager: Why use persist() over merge()?
EntityManager.merge() can insert new objects and update existing ones.
15 Answers
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SQL keys, MUL vs PRI vs UNI
What is the difference between MUL , PRI and UNI in MySQL?
4 Answers
4
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How to programmatically send SMS on the iPhone?
Does anybody know if it's possible, and how, to programmatically send a SMS from the iPhone , with the official SDK / Cocoa Touch?
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Why is it string.join(list) instead of list.join(string)?
...e any iterable can be joined (e.g, list, tuple, dict, set), but the result and the "joiner" must be strings.
For example:
'_'.join(['welcome', 'to', 'stack', 'overflow'])
'_'.join(('welcome', 'to', 'stack', 'overflow'))
'welcome_to_stack_overflow'
Using something else than strings will raise t...
Why does Hibernate require no argument constructor?
I got this hand-wavy answer but could somebody explain further? Thanks
9 Answers
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Printf width specifier to maintain precision of floating-point value
...eventh = 1.0/7.0 results in the value below. Also shown are the preceding and following representable double floating point numbers.
OneSeventh before = 0.1428571428571428 214571170656199683435261249542236328125
OneSeventh = 0.1428571428571428 49212692681248881854116916656494140625
OneSeven...
Favicon dimensions? [duplicate]
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Short answer
The favicon is supposed to be a set of 16x16, 32x32 and 48x48 pictures in ICO format. ICO format is different than PNG. Non-square pictures are not supported.
To generate the favicon, for many reasons explained below, I advise you to use this favicon generator. Full disclosure...
INSTALL_FAILED_UPDATE_INCOMPATIBLE when I try to install compiled .apk on device
I've compiled Trebuchet launcher from CyanogenMod 9, and trying to install it with adb:
29 Answers
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Background ListView becomes black when scrolling
...reate a scrollable list with every row containing a Image on the left side and some text on the right side:
11 Answers
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What is time_t ultimately a typedef to?
I searched my Linux box and saw this typedef:
10 Answers
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