大约有 15,000 项符合查询结果（耗时：0.0274秒） [XML]
'IF' in 'SELECT' statement - choose output value based on column values
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SELECT id,
IF(type = 'P', amount, amount * -1) as amount
FROM report
See http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of...
Is there any difference between GROUP BY and DISTINCT
...CT and distinct by UNION cause an oracle error, but GROUP BY worked; I was selecting only 1 column from a view and not using any aggregation; I'm still baffled why it required it, but it does confirm there is some difference in the execution. As others point out, it also lets you GROUP BY columns no...
date format yyyy-MM-ddTHH:mm:ssZ
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One option could be converting DateTime to ToUniversalTime() before converting to string using "o" format. For example,
var dt = DateTime.Now.ToUniversalTime();
Console.WriteLine(dt.ToString("o"));
It will output:
2016-01-31T20:16:01.909234...
Validate that a string is a positive integer
... but if that results in a blank string, restores a single 0.
Number(str): Convert str to a number; the number may well have a fractional portion, or may be NaN.
Math.floor: Truncate the number (chops off any fractional portion).
String(...): Converts the result back into a normal decimal string. Fo...
parseInt vs unary plus, when to use which?
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The unary + on the other hand will return NaN if the entire string is non-convertible to a number.
parseInt('2a',10) === 2; //true
parseFloat('2a') === 2; //true
isNaN(+'2a'); //true
As seen in the comment of @Alex K., parseInt and parseFloat will parse by character. This means ...
PHP - iterate on string characters
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Step 1: convert the string to an array using the str_split function
$array = str_split($your_string);
Step 2: loop through the newly created array
foreach ($array as $char) {
echo $char;
}
You can check the PHP docs for more in...
Insert all values of a table into another table in SQL
.... But the insert statement accepts values, but i would like it to accept a select * from the initial_Table. Is this possible?
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PhpStorm wrap/surround selection?
... to wrap a certain part of text. Is there any shortcut to wrap the current selection, for example:
4 Answers
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The tilde operator in C
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@MarcusJ Yes, one's complement works for converting signed to unsigned (signed->unsigned). (Note though it's easier to just assign the value to a variable declared differently and lett the compiler worry about it.) But it does not work the other way around (unsig...
Adding options to a using jQuery?
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This did NOT work in IE8 (yet did in FF):
$("#selectList").append(new Option("option text", "value"));
This DID work:
var o = new Option("option text", "value");
/// jquerify the DOM object 'o' so we can use the html method
$(o).html("option text");
$("#selectList").a...