大约有 44,000 项符合查询结果(耗时:0.0184秒) [XML]

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In Ruby, is there an Array method that combines 'select' and 'map'?

... I usually use map and compact together along with my selection criteria as a postfix if. compact gets rid of the nils. jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1} => [3, 3, 3, nil, nil, nil] jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}.compact => ...
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SELECT INTO Variable in MySQL DECLARE causes syntax error?

I´d like to SELECT a single value into a variable. I´d tried to following: 11 Answers ...
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Why is SELECT * considered harmful?

Why is SELECT * bad practice? Wouldn't it mean less code to change if you added a new column you wanted? 15 Answers ...
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Index of Currently Selected Row in DataGridView

It's that simple. How do I get the index of the currently selected Row of a DataGridView ? I don't want the Row object, I want the index (0 .. n). ...
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Insertion Sort vs. Selection Sort

I am trying to understand the differences between Insertion Sort and Selection Sort. 20 Answers ...
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How to declare a variable in MySQL?

...at has not been initialized, it has a value of NULL and a type of string. SELECT @var_any_var_name You can initialize a variable using SET or SELECT statement: SET @start = 1, @finish = 10; or SELECT @start := 1, @finish := 10; SELECT * FROM places WHERE place BETWEEN @start AND @finish...
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getting the ng-object selected with ng-change

Given the following select element 10 Answers 10 ...
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How to select all instances of a variable and edit variable name in Sublime

If I select a variable (not just any string) in my code, all other instances of that variable get a stroke (white outline) around them: ...
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MySQL: Insert record if not exists in table

...oDB; Insert a record: INSERT INTO table_listnames (name, address, tele) SELECT * FROM (SELECT 'Rupert', 'Somewhere', '022') AS tmp WHERE NOT EXISTS ( SELECT name FROM table_listnames WHERE name = 'Rupert' ) LIMIT 1; Query OK, 1 row affected (0.00 sec) Records: 1 Duplicates: 0 Warnings: 0 ...
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How to get multiple counts with one SQL query?

...tion. This is basically the same thing as a PIVOT function in some RDBMS: SELECT distributor_id, count(*) AS total, sum(case when level = 'exec' then 1 else 0 end) AS ExecCount, sum(case when level = 'personal' then 1 else 0 end) AS PersonalCount FROM yourtable GROUP BY distributor_id ...