大约有 43,000 项符合查询结果（耗时：0.0298秒） [XML]
Join vs. sub-query
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@JinghuiNiu Customers who bought expensive items: select custid from cust join bought using (custid) where price > 500. If a customer bought multiple expensive items, you'll get double-ups. To fix this, select custid from cust where exists (select * from bought where cust...
How do you use script variables in psql?
...t myvariable value
... and can then be substituted, for example, as ...
SELECT * FROM :myvariable.table1;
... or ...
SELECT * FROM table1 WHERE :myvariable IS NULL;
edit: As of psql 9.1, variables can be expanded in quotes as in:
\set myvariable value
SELECT * FROM table1 WHERE column1 ...
Can we pass parameters to a view in SQL?
..., like:
CREATE FUNCTION v_emp (@pintEno INT)
RETURNS TABLE
AS
RETURN
SELECT * FROM emp WHERE emp_id=@pintEno;
This allows you to use it as a normal view, with:
SELECT * FROM v_emp(10)
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Select all columns except one in MySQL?
I'm trying to use a select statement to get all of the columns from a certain MySQL table except one. Is there a simple way to do this?
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Can someone explain collection_select to me in clear, simple terms?
I am going through the Rails API docs for collection_select and they are god-awful.
2 Answers
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How can I run MongoDB as a Windows service?
...he following error: Cannot open MongoDB service
on computer '.'.
At line:1 char:1
+ Start-Service MongoDB
+ ~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OpenError: (System.ServiceProcess.ServiceController:ServiceController) [Start-Service],
ServiceCommandException
+ FullyQualifiedError...
Run PostgreSQL queries from the command line
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psql -U username -d mydatabase -c 'SELECT * FROM mytable'
If you're new to postgresql and unfamiliar with using the command line tool psql then there is some confusing behaviour you should be aware of when you've entered an interactive session.
For example, ...
How can I copy the output of a command directly into my clipboard?
...mewhere else other than a X application, try this one:
cat file | xclip -selection clipboard
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Search for selection in vim
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Check this Vim tip: Search for visually selected text
Or you can simply yank the selected text with y and go to search mode /, then you can paste the last yanked text with Ctrl+R 0
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Eclipse jump to closing brace
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edit: as mentioned by Romaintaz below, you can also get Eclipse to auto-select all of the code between two curly braces simply by double-clicking to the immediate right of a opening brace.
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