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Get top 1 row of each group
I have a table which I want to get the latest entry for each group. Here's the table:
20 Answers
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How to get ID of the last updated row in MySQL?
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I've found an answer to this problem :)
SET @update_id := 0;
UPDATE some_table SET column_name = 'value', id = (SELECT @update_id := id)
WHERE some_other_column = 'blah' LIMIT 1;
SELECT @update_id;
EDIT by aefxx
This technique can be further expanded to retrieve the ID of every row affected by...
Getting “Lock wait timeout exceeded; try restarting transaction” even though I'm not using a transac
... holding a record lock on some record (you're updating every record in the table!) for too long, and your thread is being timed out.
You can see more details of the event by issuing a
SHOW ENGINE INNODB STATUS
after the event (in sql editor). Ideally do this on a quiet test-machine.
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Change MySQL default character set to UTF-8 in my.cnf?
...y.cnf settings worked for me as well. Additionally, I had to make sure the table was set properly, such as ALTER TABLE Table CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;
– Chris Livdahl
May 26 '11 at 19:26
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How to persist a property of type List in JPA?
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@Please_Dont_Bully_Me_SO_Lords It is less suitable for that use case since your data will be in the database as "foo;bar;foobar". If you want to query for the data then probably an ElementCollection + JoinTable is the way to go for your situation.
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How to remove an element slowly with jQuery?
...otstrap.min.css" rel="stylesheet"/>
</head>
<body>
<table class="table table-striped table-bordered table-hover">
<thead>
<tr>
<th>id</th>
<th>firstname</th>
<th>lastname</th>
<th&g...
Margin while printing html page
...tyle will not adjust the margin in the printer driver that defines the printable area of the printer, or margin controlled by the browser (may be adjustable in print preview on some browsers)... It will just set margin on the document inside the printable area.
You should also be aware that IE7++ ...
How to implement LIMIT with SQL Server?
...s for 2000 and below versions...
SELECT TOP 10 * FROM (SELECT TOP 20 FROM Table ORDER BY Id) ORDER BY Id DESC
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MySQL Like multiple values
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Why not you try REGEXP. Try it like this:
SELECT * FROM table WHERE interests REGEXP 'sports|pub'
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JavaScript hashmap equivalent
...ipt is a high-level language. Its basic primitive (Object) includes a hash table to keep properties. This hash table is usually written in a low-level language for efficiency. Using a simple object with string keys we use an efficiently implemented hash table without any efforts on our part.
How do ...