大约有 48,000 项符合查询结果(耗时:0.0782秒) [XML]

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How to select a CRAN mirror in R

... Repository selection screen cannot be shown on your system (OS X), since OS X no longer includes X11. R tries to show you the prompt through X11. Install X11 from http://xquartz.macosforge.org/landing/. Then run the install command. The...
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typecast string to integer - Postgres

...ur value is an empty string, you can use NULLIF to replace it for a NULL: SELECT NULLIF(your_value, '')::int share | improve this answer | follow | ...
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SQL statement to get column type

... Using SQL Server: SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'yourTableName' AND COLUMN_NAME = 'yourColumnName' share |...
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PostgreSQL - max number of parameters in “IN” clause?

... explain select * from test where id in (values (1), (2)); QUERY PLAN Seq Scan on test (cost=0.00..1.38 rows=2 width=208) Filter: (id = ANY ('{1,2}'::bigint[])) But if try 2nd query: explain select * from test where id = an...
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ASP.NET MVC How to convert ModelState errors to json

... You can put anything you want to inside the select clause: var errorList = (from item in ModelState where item.Value.Errors.Any() select item.Value.Errors[0].ErrorMessage).ToList(); EDIT: You can extract multiple errors into separate list items by a...
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How can I list all foreign keys referencing a given table in SQL Server?

...get around this by creating a table, store the result into the table, then select the specific columns. Check out this link for an example :). – John Odom Apr 28 '15 at 19:04 3 ...
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How can I know which radio button is selected via jQuery?

I have two radio buttons and want to post the value of the selected one. How can I get the value with jQuery? 37 Answers ...
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jQuery select by attribute using AND and OR operators

I'm thinking about, if it is possible in jQuery to select elements by named attributes using AND and OR. 8 Answers ...
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How do you count the number of occurrences of a certain substring in a SQL varchar?

...mparing the lengths Declare @string varchar(1000) Set @string = 'a,b,c,d' select len(@string) - len(replace(@string, ',', '')) share | improve this answer | follow ...
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Select something that has more/less than x character

Was wondering if it's possible to select something that has more/less than x characters in SQL. 4 Answers ...