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SQL how to increase or decrease one for a int column in one command
...wer the second:
There are several ways to do this. Since you did not specify a database, I will assume MySQL.
INSERT INTO table SET x=1, y=2 ON DUPLICATE KEY UPDATE x=x+1, y=y+2
REPLACE INTO table SET x=1, y=2
They both can handle your question. However, the first syntax allows for more flexi...
delete_all vs destroy_all?
...
You are right. If you want to delete the User and all associated objects -> destroy_all
However, if you just want to delete the User without suppressing all associated objects -> delete_all
According to this post : Rails :dependent =...
How to get a table cell value using jQuery?
...
If you can, it might be worth using a class attribute on the TD containing the customer ID so you can write:
$('#mytable tr').each(function() {
var customerId = $(this).find(".customerIDCell").html();
});
Essentia...
Why should I prefer single 'await Task.WhenAll' over multiple awaits?
...t propagates all errors at once. With the multiple awaits, you lose errors if one of the earlier awaits throws.
Another important difference is that WhenAll will wait for all tasks to complete even in the presence of failures (faulted or canceled tasks). Awaiting manually in sequence would cause un...
Using LIMIT within GROUP BY to get N results per group?
...table.id, yourtable.year DESC;
Please see fiddle here.
Please note that if more than one row can have the same rate, you should consider using GROUP_CONCAT(DISTINCT rate ORDER BY rate) on the rate column instead of the year column.
The maximum length of the string returned by GROUP_CONCAT is lim...
Set timeout for ajax (jQuery)
... timeout
})
).then(function(){
//do something
}).catch(function(e) {
if(e.statusText == 'timeout')
{
alert('Native Promise: Failed from timeout');
//do something. Try again perhaps?
}
});
jQuery 1.8+
$.ajax({
url: '/getData',
timeout:3000 //3 second timeout
}).done...
Java: function for arrays like PHP's join()?
...
If you were looking for what to use in android, it is:
String android.text.TextUtils.join(CharSequence delimiter, Object[] tokens)
for example:
String joined = TextUtils.join(";", MyStringArray);
...
get the latest fragment in backstack
How can I get the latest fragment instance added in backstack (if I do not know the fragment tag & id)?
17 Answers
...
What is the MySQL VARCHAR max size?
... Column Count and Row Size.
Maximum size a single column can occupy, is different before and after MySQL 5.0.3
Values in VARCHAR columns are variable-length strings. The length can be specified as a value from 0 to 255 before MySQL 5.0.3, and 0 to 65,535 in 5.0.3 and later versions. The effect...
What is the “owning side” in an ORM mapping?
...y. In this case Hibernate tracks both sides of the relation independently: If you add a document to relation Person.idDocuments, it inserts a record in the association table PERSON_ID_DOCUMENTS.
On the other hand, if we call idDocument.setPerson(person), we change the foreign key person_id on table...