大约有 49,000 项符合查询结果（耗时：0.0371秒） [XML]
Is there any performance gain in indexing a boolean field?
...
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), ...
Using IntelliJ to amend git commit message
...
Amend is supported: invoke "Commit Changes" and select the checkbox "Amend commit" in the Commit Dialog. Then press "Commit" button, and the commit will be amended to the previous one.
However, the support is limited:
you can't see the details of the commit being amend...
How can I convert a string to upper- or lower-case with XSLT?
...hod of case conversion is translate():
<xsl:variable name="lowercase" select="'abcdefghijklmnopqrstuvwxyz'" />
<xsl:variable name="uppercase" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'" />
<xsl:template match="/">
<xsl:value-of select="translate(doc, $lowercase, $uppercase)" /&g...
How to convert all tables from MyISAM into InnoDB?
...database here first
//
// Actual code starts here
$sql = "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'your_database_name'
AND ENGINE = 'MyISAM'";
$rs = mysql_query($sql);
while($row = mysql_fetch_array($rs))
{
$tbl = ...
JPA eager fetch does not join
...
JPA doesn't provide any specification on mapping annotations to select fetch strategy. In general, related entities can be fetched in any one of the ways given below
SELECT => one query for root entities + one query for related mapped entity/collection of each root entity = (n+1) que...
Faster way to develop and test print stylesheets (avoid print preview every time)?
...P (Mac) or Ctrl+Shift+P (Windows, Linux))
2. Start typing Rendering and select Show Rendering.
3. For the Emulate CSS Media dropdown, select print.
UPDATE 29/02/2016
The DevTools docs have moved and the above link provides inaccurate information. The updated docs regarding Media type em...
How to remove selected commit log entries from a Git repository while keeping their changes?
I would like to remove selected commit log entries from a linear commit tree, so that the entries do not show in the commit log.
...
Inefficient jQuery usage warnings in PHPStorm IDE
...o find a solution thanks to Scott Kosman here.
Basically the answer is to select IDs individually and then use .find(...) for anything below. So taking your example:
$("#property [data-role='content'] .container");
Changing it to this makes PhpStorm happy and can evidently be more than twice as ...
How to “add existing frameworks” in Xcode 4?
...
As per Apple's documentation:
In the project navigator, select
your project.
Select your target.
Select the "Build Phases" tab.
Open "Link Binaries With Libraries"
expander.
Click the + button.
Select your framework.
(optional) Drag and drop the added
framework to the "Framework...
How to find largest objects in a SQL Server database?
...quite a bit understanding and determining the size of indices and tables:
SELECT
t.name AS TableName,
i.name as indexName,
sum(p.rows) as RowCounts,
sum(a.total_pages) as TotalPages,
sum(a.used_pages) as UsedPages,
sum(a.data_pages) as DataPages,
(sum(a.total_pages) *...