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What is the difference between JOIN and UNION?
...) and involves using the foreign key in one table to look up column values by using the primary key in another.
Now compare the above depiction with that of a union. In a union each row within the result is from one table OR the other. In a union, columns aren’t combined to create results, rows...
Find rows with multiple duplicate fields with Active Record, Rails & Postgres
...
Based on the answer above by @newUserNameHere I believe the right way to show the count for each is
res = User.select('first, email, count(1)').group(:first,:email).having('count(1) > 1')
res.each {|r| puts r.attributes } ; nil
...
How to check if a database exists in SQL Server?
... data type. COLUMN_PRIVILEGES Every column with a privilege granted to or by the current user in the current database. COLUMNS Lists every column in the system CONSTRAINT_COLUMN_USAGE Every column that has a constraint defined on it. CONSTRAINT_TABLE_USAGE Every table that has a constraint defin...
How to sort an array by a date property
... 1 : 0;
});
Generic, Powerful Answer
Define a custom non-enumerable sortBy function using a Schwartzian transform on all arrays :
(function(){
if (typeof Object.defineProperty === 'function'){
try{Object.defineProperty(Array.prototype,'sortBy',{value:sb}); }catch(e){}
}
if (!Array.prot...
XDocument or XmlDocument
...e extent. For example, you can stream a large document but use LINQ to XML by positioning an XmlReader at the start of an element, reading an XElement from it and processing it, then moving on to the next element etc. There are various blog posts about this technique, here's one I found with a quick...
Why does JPA have a @Transient annotation?
... in Java refers to the process of encoding/decoding an object's state as a byte stream.
The transient keyword is a stronger condition than @Transient:
If a field uses the transient keyword, that field will not be serialized when the object is converted to a byte stream. Furthermore, since JPA tre...
Pass entire form as data in jQuery Ajax function
...on is to make a FormData and send it:
var myform = document.getElementById("myform");
var fd = new FormData(myform );
$.ajax({
url: "example.php",
data: fd,
cache: false,
processData: false,
contentType: false,
type: 'POST',
succes...
Is there a way of having git show lines added, lines changed and lines removed?
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The output of git diff --numstat is broken down by file. To see the total added/removed for the diff, you can pipe it to awk: git diff --numstat | awk '{ added += $1; removed += $2 } END { print "+" added " -" removed }'
– hughes
Dec ...
How to change the type of a field?
...tion of Strings with 0-index-item x.bad value. Variant ""+x.bad, described by Simone works as desired - creates String value instead of Int32
– Dao
Jul 30 '12 at 16:36
...
jQuery UI Sortable, then write order into a database
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I can change the rows by following the accepted answer and associated example on jsFiddle. But due to some unknown reasons, I couldn't get the ids after "stop or change" actions. But the example posted in the JQuery UI page works fine for me. You ...