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Remove Primary Key in MySQL
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Note that you have a composite PRIMARY KEY which covers all three columns and id is not guaranteed to be unique.
If it happens to be unique, you can make it to be a PRIMARY KEY and AUTO_INCREMENT again:
ALTER TABLE user_customer_permission MODIFY id INT NOT NULL PRIMARY KEY AUTO_INCREMENT;
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Why does cURL return error “(23) Failed writing body”?
...it wants it will close the read stream from curl. cURL doesn't expect this and emits the "Failed writing body" error.
A workaround is to pipe the stream through an intermediary program that always reads the whole page before feeding it to the next program.
E.g.
curl "url" | tac | tac | grep -qs f...
Javascript when to use prototypes
I'd like to understand when it is appropriate to use prototype methods in js. Should they always be used? Or are there cases where using them is not preferred and/or incurs a performance penalty?
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Using Git, show all commits that are in one branch, but not the other(s)
... Note that git log foo..bar will show the commits between bar's latest and foo's latest, but not other commits missing from further back in time. To see everything in bar but not in foo, you should use @jimmyorr's solution.
– Paul A Jungwirth
Jul 10 '14 at ...
How do I truncate a .NET string?
...length is not longer than a given value. I am writing to a database table and want to ensure that the values I write meet the constraint of the column's datatype.
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二进制数据专题：蓝牙、Socket、WebSocket、MQTT 收发字节 · App Inventor 2 中文网
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这些生成工程已通过实际后台导入、原始积木载入及 Android APK 编译检查，详见验证记录。尚未验证浏览器人工导入、AI 伴侣和真机运行。下表提供复核与联调步骤；遇到差异时以实际结果为准。
保留本页原有组合用法，在...
Convert a Unicode string to a string in Python (containing extra symbols)
...hat) containing some currency symbols to a "Python string" (whatever ...) and you think that a remove-some-diacritics delete-other-non-ascii characters kludge answers his question???
– John Machin
Jul 30 '09 at 16:25
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All possible array initialization syntaxes
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These are the current declaration and initialization methods for a simple array.
string[] array = new string[2]; // creates array of length 2, default values
string[] array = new string[] { "A", "B" }; // creates populated array of length 2
string[] array = ...
What does bundle exec rake mean?
...does bundle exec rake db:migrate mean? Or just bundle exec rake <command> in general?
7 Answers
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How to get the ActionBar height?
...tionBar (using Sherlock) every time an activity is created (specially to handle configuration changes on rotation where the ActionBar height might change).
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