大约有 3,551 项符合查询结果（耗时：0.0309秒） [XML]
Linear Regression and group by in R
...s not seem very R-like, however. In SAS I would do a 'by' statement and in SQL I would do a 'group by'. What's the R way of doing this?
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How do you delete an ActiveRecord object?
... runs callbacks, so before it deletes anything, it loads records. It's two SQL statements not one. Aside from the performance implications, this has concurrency implications too. The safer call skips callbacks; User.delete_all() will issue just a single DELETE FROM... command.
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Multiple select statements in Single query
I am generating a report in php (mysql),
6 Answers
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How does a “stack overflow” occur and how do you prevent it?
...e and server stack you're using. It is possible to blow the stack on your SQL server, for instance.
-Adam
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How to add one day to a date? [duplicate]
...er compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java ...
calculating the difference in months between two dates
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This seems to be the same logic used by the Sql Server DateDiff(month, ...) function. It also has the advantage of being extremely concise and easy to explain and understand. I would explain it as follows... how many pages in the calendar would you have to turn to get ...
How do you implement a good profanity filter?
...estion that also has a PHP example (the main valuable part in there is the SQL-based filtered word approach -- the leet-speak compensator can be dispensed with if you find it unnecessary).
You also added: "Getting the list of words in the first place is the real question." -- in addition to some o...
PowerShell says “execution of scripts is disabled on this system.”
... across a similar question on SF site, "Powershell execution policy within SQL Server” asked Oct 10 '14. The answers there included Get-ExecutionPolicy -List which helped me to see the different scopes. The cmd Get-ExecutionPolicy does not show all the scopes. Import-Module SQLPS is now working...
JavaScript: client-side vs. server-side validation
...ch depends on related data. Developers regularly screw this up, but PostgreSQL provides some good solutions.
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Logging errors in ASP.NET MVC
... page level. It can be configured to log to various different places (like SQL Server, Email etc). It also provides a web frontend, so that you can browse through the log of exceptions.
Its the first thing I add to any asp.net mvc app I create.
I still use log4net, but I tend to use it for logging...