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What can , and be used for?
...tadata>
does basically the following:
Get the request parameter value by name id.
Convert and validate it if necessary (you can use required, validator and converter attributes and nest a <f:converter> and <f:validator> in it like as with <h:inputText>)
If conversion and valid...
How to submit a form with JavaScript by clicking a link?
...id">submit</button>
</form>
var form = document.getElementById("form-id");
document.getElementById("your-id").addEventListener("click", function () {
form.submit();
});
Enclose the latter JavaScript code by an DOMContentLoaded event (choose only load for backward compatiblity) ...
Random record in ActiveRecord
...del.first(:offset => offset)
To be honest, I've just been using ORDER BY RAND() or RANDOM() (depending on the database). It's not a performance issue if you don't have a performance issue.
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How to debug Lock wait timeout exceeded on MySQL?
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What gives this away is the word transaction. It is evident by the statement that the query was attempting to change at least one row in one or more InnoDB tables.
Since you know the query, all the tables being accessed are candidates for being the culprit.
From there, you should be ...
1052: Column 'id' in field list is ambiguous
...
SQL supports qualifying a column by prefixing the reference with either the full table name:
SELECT tbl_names.id, tbl_section.id, name, section
FROM tbl_names
JOIN tbl_section ON tbl_section.id = tbl_names.id
...or a table alias:
SELECT n.id, s.id, n.n...
How to check which locks are held on a table
..., but this may helpful to you.
You can check which statements are blocked by running this:
select cmd,* from sys.sysprocesses
where blocked > 0
It will also tell you what each block is waiting on. So you can trace that all the way up to see which statement caused the first block that caused ...
Rails 3: Get Random Record
...e id >= trunc(
random() * (select max(id) from my_table) + 1
)
order by id
limit 1;
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wget/curl large file from google drive
...API
Basically you have to create a public directory and access your files by relative reference with something like
wget https://googledrive.com/host/LARGEPUBLICFOLDERID/index4phlat.tar.gz
Alternatively, you can use this script: https://github.com/circulosmeos/gdown.pl
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Django database query: How to get object by id?
...turns the identity of an object. In a majority of cases referencing things by id will do the right thing e.g. Class.objects.get(id=this_object_id) work. But that's something to consider I guess.
– Tom
Jul 28 '16 at 20:45
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MySQL Insert Where query
...t does a DELETE (which may be a no-op if the row does not exist), followed by an INSERT. Think of the consequences vis. triggers and foreign key dependencies. Instead, use INSERT...ON DUPLICATE KEY UPDATE.
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