大约有 40,000 项符合查询结果(耗时:0.0337秒) [XML]

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MySQL: Fastest way to count number of rows

...olumn indexes, so it will be the best result. Mysql with MyISAM engine actually stores row count, it doensn't count all rows each time you try to count all rows. (based on primary key's column) Using PHP to count rows is not very smart, because you have to send data from mysql to php. Why do it whe...
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Is it possible to preview stash contents in git?

...shows the last tone, 1 the second last one.. etc. git stash list will show all the available. – brita_ Jul 18 '14 at 21:13 7 ...
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How can I check a C# variable is an empty string “” or null? [duplicate]

... @Lion Liu: Actually I think PHP has exactly as much to offer. See: php.net/manual/en/function.empty.php – Milan Feb 2 '16 at 20:09 ...
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What is the difference between statically typed and dynamically typed languages?

I hear a lot that new programming languages are dynamically typed but what does it actually mean when we say a language is dynamically typed vs. statically typed? ...
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Perform .join on value in array of objects

...Array.prototype.map is what you're looking for if you want to code functionally. [ {name: "Joe", age: 22}, {name: "Kevin", age: 24}, {name: "Peter", age: 21} ].map(function(elem){ return elem.name; }).join(","); In modern JavaScript: [ {name: "Joe", age: 22}, {name: "Kevin", age: 2...
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Why are dates calculated from January 1st, 1970?

...1st, 1970) as default standard The Question makes two false assumptions: All time-tracking in computing is done as a count-since-1970. Such tracking is standard. Two Dozen Epochs Time in computing is not always tracked from the beginning of 1970 UTC. While that epoch reference is popular, various...
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What's the difference between utf8_general_ci and utf8_unicode_ci?

...languages or characters. On modern servers, this performance boost will be all but negligible. It was devised in a time when servers had a tiny fraction of the CPU performance of today's computers. Benefits of utf8mb4_unicode_ci over utf8mb4_general_ci utf8mb4_unicode_ci, which uses the Unicode r...
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counting number of directories in a specific directory

... can instead test the directory's children and do not descend into them at all: $ find .vim/* -maxdepth 0 -type d .vim/after .vim/autoload .vim/bundle .vim/colors .vim/compiler .vim/doc .vim/ftdetect .vim/ftplugin .vim/indent .vim/plugin .vim/syntax $ find .vim/* -maxdepth 0 -type d | wc -l 11 $ f...
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Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=

...: SET @rUsername = ‘aname’ COLLATE utf8_unicode_ci; -- COLLATE added CALL updateProductUsers(@rUsername, @rProductID, @rPerm); Option 2: add COLLATE to the WHERE clause: CREATE PROCEDURE updateProductUsers( IN rUsername VARCHAR(24), IN rProductID INT UNSIGNED, IN rPerm VARCHAR(16...
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Nginx no-www to www and www to no-www

...n.php last; # etc etc... } } Note: I have not originally included https:// in my solution since we use loadbalancers and our https:// server is a high-traffic SSL payment server: we do not mix https:// and http://. To check the nginx version, use nginx -v. Strip www from ...