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SQL query to get all values a enum can have
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The unnest call will return records of type myenum with a column name of "myenum". You might also want to cast the enum to text and specify a column name by adding something like. ::text AS my_column
– Justin Oh...
Test if a variable is set in bash when using “set -o nounset”
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Nope, -, +, :+, and :- are all supported. The former detect whether the variable is set, and the latter detect whether it is set or empty. From man bash: "Omitting the colon results in a test only for a parameter that is unset."
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How can I get the MD5 fingerprint from Java's keytool, not only SHA-1?
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With JDK 1.7 installed, keytool always outputs by default SHA1 fingerprint, not MD5.
you can get the MD5 Certificate by adding -v option.
use the following code:-
C:\Program Files\Java\jdk1.7.0\bin>keytool -v -list -alias
androiddebugke...
What are the advantages of using a schema-free database like MongoDB compared to a relational databa
...ire several tables to properly represent in a relational db. This is especially useful if your data is immutable.
Deep query-ability. MongoDB supports dynamic queries on documents using a document-based query language that's nearly as powerful as SQL.
No schema migrations. Since MongoDB is schema-...
Performing Breadth First Search recursively
...tion, but I suppose I could imagine some bizarre scenario where you're not allowed any heap space for some reason [some really bad custom memory manager? some bizarre runtime/OS issues?] while you still have access to the stack...)
Breadth-first traversal traditionally uses a queue, not a stack. T...
How do HashTables deal with collisions?
...lookups in hash tables very slow.
Option 2: If the hash table entries are all full then the hash table can increase the number of buckets that it has and then redistribute all the elements in the table. The hash function returns an integer and the hash table has to take the result of the hash funct...
How to handle configuration in Go [closed]
I'm new at Go programming, and I'm wondering: what is the preferred way to handle configuration parameters for a Go program (the kind of stuff one might use properties files or ini files for, in other contexts)?
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How do I measure the execution time of JavaScript code with callbacks?
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Use the Node.js console.time() and console.timeEnd():
var i;
console.time("dbsave");
for(i = 1; i < LIMIT; i++){
db.users.save({id : i, name : "MongoUser [" + i + "]"}, end);
}
end = function(err, saved) {
console.log(( err || !saved )?"Error...
How to specify an area name in an action link?
... This is a very good tip! But it gives not expected results with MVC 2.. Small correction - Html.ActionLink("home", "Index", new { area = "", controller = "Home" })
– Alexander Beletsky
Nov 20 '10 at 10:36
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Java String - See if a string contains only numbers and not letters
I have a string that I load throughout my application, and it changes from numbers to letters and such. I have a simple if statement to see if it contains letters or numbers but, something isn't quite working correctly. Here is a snippet.
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