大约有 30,000 项符合查询结果（耗时：0.0530秒） [XML]
MySQL foreign key constraints, cascade delete
I want to use foreign keys to keep the integrity and avoid orphans (I already use innoDB).
3 Answers
...
Seeking clarification on apparent contradictions regarding weakly typed languages
...l, there is no such thing as an "integer variable", a "float variable", a "string variable" or a "boolean variable". In fact, as far as the user can (usually) tell, there aren't even integer, float, string or boolean values: all you have are "scalars", which are all of these things at the same time...
What does = +_ mean in JavaScript
... to converts it into a number, if it isn't
already. [...] It can convert string representations of integers and
floats, as well as the non-string values true, false, and null.
Integers in both decimal and hexadecimal ("0x"-prefixed) formats are
supported. Negative numbers are supported (thou...
How to detect the current OS from Gradle
...ncl. FreeBSD and Solaris).
import org.gradle.internal.os.OperatingSystem
String osName = OperatingSystem.current().getName();
String osVersion = OperatingSystem.current().getVersion();
println "*** $osName $osVersion was detected."
if (OperatingSystem.current().isLinux()) {
// Consider Linux....
How do I check CPU and Memory Usage in Java?
... Runtime.getRuntime();
NumberFormat format = NumberFormat.getInstance();
StringBuilder sb = new StringBuilder();
long maxMemory = runtime.maxMemory();
long allocatedMemory = runtime.totalMemory();
long freeMemory = runtime.freeMemory();
sb.append("free memory: " + format.format(freeMemory / 1024)...
TypeLoadException says 'no implementation', but it is implemented
...faceDef, add just one class, and build:
public interface IInterface
{
string GetString(string key);
//short GetShort(string key);
}
Create a second class library project: Implementation (with separate solution), copy InterfaceDef.dll into project directory and add as file reference, add ju...
How to add url parameters to Django template url tag?
...ccept the param in the regex:
(urls.py)
url(r'^panel/person/(?P<person_id>[0-9]+)$', 'apps.panel.views.person_form', name='panel_person_form'),
So you use this in your template:
{% url 'panel_person_form' person_id=item.id %}
If you have more than one param, you can change your regex and...
How do you use the “WITH” clause in MySQL?
...)
The request for the feature dates back to 2006.
As mentioned, you provided a poor example - there's no need to perform a subselect if you aren't altering the output of the columns in any way:
SELECT *
FROM ARTICLE t
JOIN USERINFO ui ON ui.user_userid = t.article_ownerid
JOIN CAT...
File content into unix variable with newlines
..., it's actually the echo doing this. You need simply put quotes around the string to maintain those newlines:
echo "$testvar"
This wil give the result you want. See the following transcript for a demo:
pax> cat num1.txt ; x=$(cat num1.txt)
line 1
line 2
pax> echo $x ; echo '===' ; echo "$...
How to Save Console.WriteLine Output to Text File
... replace Console.WriteLine with Logger.Out.
At the end write to a file the string Log
public static class Logger
{
public static StringBuilder LogString = new StringBuilder();
public static void Out(string str)
{
Console.WriteLine(str);
LogString.Append(str...