大约有 40,000 项符合查询结果(耗时:0.0945秒) [XML]

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Postgresql query between date ranges

... things become simpler if you use >= start AND < end. For example: SELECT user_id FROM user_logs WHERE login_date >= '2014-02-01' AND login_date < '2014-03-01' In this case you still need to calculate the start date of the month you need, but that should be straight forw...
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Write a number with two decimal places SQL server

... try this SELECT CONVERT(DECIMAL(10,2),YOURCOLUMN) share | improve this answer | follow | ...
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data.table vs dplyr: can one do something well the other can't or does poorly?

... ## data.table syntax left_join(DT2, DT1) ## dplyr syntax # 2. select columns while join DT1[DT2, .(z, i.mul)] left_join(select(DT2, x, y, mul), select(DT1, x, y, z)) # 3. aggregate while join DT1[DT2, .(sum(z) * i.mul), by = .EACHI] DF1 %>% group_by(x, y) %>% summarise(z = su...
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Best way to check if object exists in Entity Framework?

... hi. how can we check if it exists and after that select all its data? – virtouso Apr 7 '15 at 1:27 1 ...
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LINQ to Entities does not recognize the method

...re(iv => alm_x_suc.Exists(axs => axs.almacen == iv.LOCNCODE.Trim())).Select(iv => iv.ITEMNMBR.Trim()).ToList(); this was the exactly error: System.NotSupportedException: 'LINQ to Entities does not recognize the method 'Boolean Exists(System.Predicate`1[conector_gp.Models.almacenes_por...
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Replace a newline in TSQL

...e any of CR, LF or CR+LF. To get them all, you need something like this: SELECT REPLACE(REPLACE(@str, CHAR(13), ''), CHAR(10), '') share | improve this answer | follow ...
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Convert Month Number to Month Name Function in SQL

... A little hacky but should work: SELECT DATENAME(month, DATEADD(month, @mydate-1, CAST('2008-01-01' AS datetime))) share | improve this answer | ...
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Keyboard shortcuts are not active in Visual Studio with Resharper installed

...ou can look at the Visual Studio Integration options for ReSharper by... Select ReSharper > Options... from the Visual Studio menu Select the Visual Studio Integration item on the Options window The bottom of the page gives instructions on how to reset the keyboard scheme. If that doesn't w...
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Selecting data frame rows based on partial string match in a column

I want to select rows from a data frame based on partial match of a string in a column, e.g. column 'x' contains the string "hsa". Using sqldf - if it had a like syntax - I would do something like: ...
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MySQL CONCAT returns NULL if any field contain NULL

... convert the NULL values with empty string by wrapping it in COALESCE SELECT CONCAT(COALESCE(`affiliate_name`,''),'-',COALESCE(`model`,''),'-',COALESCE(`ip`,''),'-',COALESCE(`os_type`,''),'-',COALESCE(`os_version`,'')) AS device_name FROM devices ...