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E11000 duplicate key error index in mongodb mongoose
... null value.
In other words, a sparse index is ok with multiple documents all having null values.
sparse indexes
From comments:
Your error says that the key is named mydb.users.$email_1 which makes me suspect that you have an index on both users.email and users.local.email (The former being old an...
Git: “Not currently on any branch.” Is there an easy way to get back on a branch, while keeping the
... hash of last commit. Checkout the branch you wish to be at, and git merge _hash_
– Daniel
May 31 '12 at 13:31
BE REAL...
Idiomatic way to convert an InputStream to a String in Scala
...uch the same thing. Not sure why you want to get lines and then glue them all back together, though. If you can assume the stream's nonblocking, you could just use .available, read the whole thing into a byte array, and create a string from that directly.
...
What is the difference between a.getClass() and A.class in Java?
...getClass() will return the B class.
A.class evaluates to the A class statically, and is used for other purposes often related to reflection.
In terms of performance, there may be a measurable difference, but I won't say anything about it because in the end it is JVM and/or compiler dependent.
T...
What does a Ajax call response like 'for (;;); { json data }' mean? [duplicate]
I found this kind of syntax being used on Facebook for Ajax calls. I'm confused on the for (;;); part in the beginning of response. What is it used for?
...
Where can I view Tomcat log files in Eclipse?
... "Arguments" tab of its launch configuration:
-Dcatalina.base="${project_loc}\<apache-tomcat-5.5.23_loc>"
-Dcatalina.home="${project_loc}\<apache-tomcat-5.5.23_loc>"
-Djava.util.logging.config.file="${project_loc}\<apache-tomcat-5.5.23_loc>\conf\logging.properties"
-Djava.uti...
Sending message through WhatsApp
...en/android/26000030/?category=5245251
WhatsApp's Click to Chat feature allows you to begin a chat with
someone without having their phone number saved in your phone's
address book. As long as you know this person’s phone number, you can
create a link that will allow you to start a chat w...
iPad/iPhone hover problem causes the user to double click a link
... ago, that use jquery mouse events...I just got an ipad and i noticed that all the mouse over events are translated in clicks...so for instance i have to do two clicks instead of one..(the first hover, than the actual click)
...
How to use QueryPerformanceCounter?
...
#include <windows.h>
double PCFreq = 0.0;
__int64 CounterStart = 0;
void StartCounter()
{
LARGE_INTEGER li;
if(!QueryPerformanceFrequency(&li))
cout << "QueryPerformanceFrequency failed!\n";
PCFreq = double(li.QuadPart)/1000.0;
QueryP...
What is the difference between currying and partial application?
...ints that other peoples examples of currying are not currying, but are actually just partial application.
14 Answers
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