大约有 47,000 项符合查询结果（耗时：0.0234秒） [XML]
C#/Linq: Apply a mapping function to each element in an IEnumerable?
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You can just use the Select() extension method:
IEnumerable<int> integers = new List<int>() { 1, 2, 3, 4, 5 };
IEnumerable<string> strings = integers.Select(i => i.ToString());
Or in LINQ syntax:
IEnumerable<int> in...
Is it possible to insert multiple rows at a time in an SQLite database?
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This can be recast into SQLite as:
INSERT INTO 'tablename'
SELECT 'data1' AS 'column1', 'data2' AS 'column2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
a note on performance
I originally used this technique to efficiently lo...
Convert Unix timestamp into human readable date using MySQL
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Use FROM_UNIXTIME():
SELECT
FROM_UNIXTIME(timestamp)
FROM
your_table;
See also: MySQL documentation on FROM_UNIXTIME().
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Programmatically trigger “select file” dialog box
I have a hidden file input element. Is it possible to trigger its select file dialog box from a button's click event?
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Is there any performance gain in indexing a boolean field?
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It depends on the actual queries and the selectivity of the index/query combination.
Case A: condition WHERE isok = 1 and nothing else there:
SELECT *
FROM tableX
WHERE isok = 1
If the index is selective enough (say you have 1M rows and only 1k have isok = 1), ...
How to get the max of two values in MySQL?
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Use GREATEST()
E.g.:
SELECT GREATEST(2,1);
Note: Whenever if any single value contains null at that time this function always returns null (Thanks to user @sanghavi7)
s...
Cause of a process being a deadlock victim
I have a process with a Select which takes a long time to finish, on the order of 5 to 10 minutes. I am currently not using NOLOCK as a hint to the MS SQL database engine. At the same time we have another process doing updates and inserts into the same database and same tables. The first pr...
Android file chooser [closed]
...ent in an Intent.createChooser() like this:
private static final int FILE_SELECT_CODE = 0;
private void showFileChooser() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("*/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
try {
startActivityForR...
Selecting and manipulating CSS pseudo-elements such as ::before and ::after using jQuery
Is there any way to select/manipulate CSS pseudo-elements such as ::before and ::after (and the old version with one semi-colon) using jQuery?
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Copying text with color from Notepad++
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In NPP v6.7.7 you can do this by selecting your text, right clicking on it, select "Plugin commands" and then "Copy text with syntax highlighting".
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