大约有 47,000 项符合查询结果(耗时:0.0395秒) [XML]

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How do I select elements of an array given condition?

... x = [5, 2, 3, 1, 4, 5] , y = ['f', 'o', 'o', 'b', 'a', 'r'] . I want to select the elements in y corresponding to elements in x that are greater than 1 and less than 5. ...
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Xcode stops working after set “xcode-select -switch”

...eloper directory, not the Xcode application bundle. Run this: sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer With recent versions of Xcode, you can go to Xcode ➙ Preferences… ➙ Locations and pick one of the options for Command Line Tools to set the location. ...
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Should MySQL have its timezone set to UTC?

...the timezone will not change the stored datetime or timestamp, but it will select a different datetime from timestamp columns Warning! UTC has leap seconds, these look like '2012-06-30 23:59:60' and can be added randomly, with 6 months prior notice, due to the slowing of the earths rotation GMT con...
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MySQL: How to copy rows, but change a few fields?

...able ( Event_ID , col2 ... ) SELECT "155" , col2 ... FROM Table WHERE Event_ID = "120" Here, the col2, ... represent the remaining columns (the ones other than Event_ID) in your table. ...
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How to export query result to csv in Oracle SQL Developer?

...worksheet toolbar) That's it. Method 2 Run a query Right click and select unload. Update. In Sql Developer Version 3.0.04 unload has been changed to export Thanks to Janis Peisenieks for pointing this out Revised screen shot for SQL Developer Version 3.0.04 From the format drop down...
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Max or Default?

...d, you can get around this limitation by casting to a nullable within your select. My VB is a little rusty, but I think it'd go something like this: Dim x = (From y In context.MyTable _ Where y.MyField = value _ Select CType(y.MyCounter, Integer?)).Max Or in C#: var x = (from y...
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How to get the number of days of difference between two dates on mysql?

...lues are used in the calculation In your case, you'd use : mysql> select datediff('2010-04-15', '2010-04-12'); +--------------------------------------+ | datediff('2010-04-15', '2010-04-12') | +--------------------------------------+ | 3 | +--------------...
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Find all tables containing column with specified name - MS SQL Server

... Search Tables: SELECT c.name AS 'ColumnName' ,t.name AS 'TableName' FROM sys.columns c JOIN sys.tables t ON c.object_id = t.object_id WHERE c.name LIKE '%MyName%' ORDER BY TableName ,C...
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Best way to test SQL queries [closed]

...value, and all values are consecutive: create view cm_absolute_month as select *, year * 12 + month as absolute_month from month_value; Now what we have to test is inherent in our spec, namely that for any tuple (year, month), there is one and only one (absolute_month), and that (absolute_month...
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How do I convert an interval into a number of hours with postgres?

... Probably the easiest way is: SELECT EXTRACT(epoch FROM my_interval)/3600 share | improve this answer | follow | ...