大约有 20,000 项符合查询结果（耗时：0.0277秒） [XML]
MySQL Great Circle Distance (Haversine formula)
...o search by kilometers instead of miles, replace 3959 with 6371.
SELECT id, ( 3959 * acos( cos( radians(37) ) * cos( radians( lat ) )
* cos( radians( lng ) - radians(-122) ) + sin( radians(37) ) * sin(radians(lat)) ) ) AS distance
FROM markers
HAVING distance < 25
ORDER BY distance
LIMIT ...
How to get process ID of background process?
...
You need to save the PID of the background process at the time you start it:
foo &
FOO_PID=$!
# do other stuff
kill $FOO_PID
You cannot use job control, since that is an interactive feature and tied to a controlling terminal. A script will ...
Jquery insert new row into table at a certain index
...$('#my_table > tbody:last').append(newRow); // this will add new row inside tbody
$("table#myTable tr").last().after(newRow); // this will add new row outside tbody
//i.e. between thead and tbody
//.befor...
Select2 doesn't work when embedded in a bootstrap modal
...in bootstrap modal, I can't type anything into it. It's like disabled? Outside the modal select2 works fine.
29 Answers
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OceanBase使用libeasy原理源码分析：客户端 - 数据库(内核) - 清泛网 - 专...
...sy_list_t session_list_node;
//为了快速根据packet id定位到发送队列中的session，将session加入到发送队列中时，同时，将其加入到一个hash表中，hash表采用链表的方式将同一个bucket的元素连接起来，
//链表元素就是easy_...
I want to execute shell commands from Maven's pom.xml
...
Here's what's been working for me:
<plugin>
<artifactId>exec-maven-plugin</artifactId>
<groupId>org.codehaus.mojo</groupId>
<executions>
<execution><!-- Run our version calculation script -->
<id>Version Calculation<...
How set maximum date in datepicker dialog in android?
...ty(), new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker arg0, int year, int month, int day_of_month) {
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, (month+1)...
What are database normal forms and can you give examples? [closed]
.... Recall that a primary key can be made up of multiple columns. As Chris said in his response:
The data depends on the key [1NF], the whole key [2NF] and nothing but the key [3NF] (so help me Codd).
2NF
Say you have a table containing courses that are taken in a certain semester, and you have the...
How to clear a chart from a canvas so that hover events cannot be triggered?
...is is my <canvas> element
$('#graph-container').append('<canvas id="results-graph"><canvas>');
canvas = document.querySelector('#results-graph');
ctx = canvas.getContext('2d');
ctx.canvas.width = $('#graph').width(); // resize to parent width
ctx.canvas.height = $('#graph...
Best design for a changelog / auditing database table? [closed]
...rted from the very minimalistic design, like the one you described:
event ID
event date/time
event type
user ID
description
The idea was the same: to keep things simple.
However, it quickly became obvious that this minimalistic design was not sufficient. The typical audit was boiling down to qu...