大约有 45,000 项符合查询结果（耗时：0.0344秒） [XML]
ALTER TABLE to add a composite primary key
...dexed from left to right.
For example, consider the following queries:
A) SELECT person, place, thing FROM provider WHERE person = 'foo' AND thing = 'bar';
B) SELECT person, place, thing FROM provider WHERE person = 'foo' AND place = 'baz';
C) SELECT person, place, thing FROM provider WHERE person ...
Is this a “good enough” random algorithm; why isn't it used if it's faster?
... |12000%n", name);
for (int i = 0; i < 10; i++) {
char[] bar = " ".toCharArray(); // 50 chars.
Arrays.fill(bar, 0, Math.max(0, Math.min(50, frequencies[i] / 100 - 80)), '#');
System.out.printf("0.%dxxx:...
PostgreSQL: Drop PostgreSQL database through command line [closed]
...rrently taking place against your database, including all idle processes.
SELECT * FROM pg_stat_activity WHERE datname='database name';
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Tools to selectively Copy HTML+CSS+JS From A Specific Element of DOM [closed]
... well. The problem was that we were taking only a part of the HTML and CSS selectors that were matching in the context of the whole document, which were not matching anymore in the context of an HTML snippet. Since parsing and modifying selectors didn't seem like a good idea, I gave up on this attem...
sqlalchemy: how to join several tables by one query?
...sn't do a join at all" - that's a little misleading. It will have sql like select x from a, b ,c which is a cross join. The filters then make it an inner join.
– Aidan Kane
Sep 12 '16 at 13:04
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Get filename and path from URI from mediastore
I have an onActivityResult returning from an mediastore image selection which I can get a URI for an image using the following:
...
Difference between JOIN and INNER JOIN
...nal,
or you can specify CROSS JOIN.
OR
For an inner join, the syntax is:
SELECT ...
FROM TableA
[INNER] JOIN TableB
(in other words, the "INNER" keyword is optional - results are the same
with or without it)
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How to get the system uptime in Windows? [closed]
...can also click CTRL+SHIFT+ESC to get to the Task Manager.
In Task Manager, select the Performance tab.
The current system uptime is shown under System or Performance ⇒ CPU for Win 8/10.
2: By using the System Information Utility
The systeminfo command line utility checks and displays various ...
How do I get the n-th level parent of an element in jQuery?
...
this will not work for multiple element selections, a safer way would be: $('.element').first().parents().eq(num);
– zzzzBov
Aug 17 '11 at 13:44
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jQuery: checking if the value of a field is null (empty)
... be null, it's always a string value. this isn't entirely true. I've got a select containing no options. When I perform .val() on this it returns null. Jquery 1.7.2
– Liam
Jan 14 '13 at 11:07
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