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javascript: Clear all timeouts?
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It need not start at 1. The HTML5 spec says "Let handle be a user-agent-defined integer that is greater than zero that will identify the timeout to be set by this call." which leaves room for the handle to be any positive integer including non-consecutive and non-small integ...
Difference Between One-to-Many, Many-to-One and Many-to-Many?
... so this is probably a trivial question but I'm having trouble visualizing and understanding the differences and when to use each. I'm also a little unclear as to how concepts like uni-directional and bi-directional mappings affect the one-to-many/many-to-many relationships. I'm using Hibernate righ...
How to check which locks are held on a table
...first block that caused the other blocks.
Edit to add comment from @MikeBlandford:
The blocked column indicates the spid of the blocking process. You can run kill {spid} to fix it.
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im...
SQL WHERE ID IN (id1, id2, …, idn)
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Option 3 is simply horrible performance-wise. It sends a query every loop and hammers the database with small queries. It also prevents it from using any optimizations for "value is one of those in a given list"
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Android OnClickListener - identify a button
...b1);
b2 = (Button) findViewById(R.id.b2);
b1.setOnClickListener(myhandler1);
b2.setOnClickListener(myhandler2);
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}
View.OnClickListener myhandler1 = new View.OnClickListener() {
public void onClick(View v) {
// it was the 1st button
}
};
View.OnClickListener ...
Handling colon in element ID with jQuery
...xplanation:
Apart from the speed gain (see further down), it is easier to handle.
Example: Say you have a function
function doStuff(id){
var jEle = $("#" + id); //is not safe, since id might be "foo:bar:baz" and thus fail.
//You would first have to look for ":" in the id string,...
How to express a NOT IN query with ActiveRecord/Rails?
...e come to this, if you are using Rails 4 look at the answers by Trung Lê` and VinniVidiVicci.
15 Answers
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How to delete from multiple tables in MySQL?
...m trying to delete from a few tables at once. I've done a bit of research, and came up with this
7 Answers
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How to get the instance id from within an ec2 instance?
... of a more advanced use (retrieve instance ID as well as availability zone and region, etc.):
EC2_INSTANCE_ID="`wget -q -O - http://169.254.169.254/latest/meta-data/instance-id || die \"wget instance-id has failed: $?\"`"
test -n "$EC2_INSTANCE_ID" || die 'cannot obtain instance-id'
EC2_AVAIL_ZONE=...
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
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