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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.
...
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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What is the difference between HAVING and WHERE in SQL?
..., CNT=Count(1)
From Address
Where State = 'MA'
Group By City
Gives you a table of all cities in MA and the number of addresses in each city.
This code:
select City, CNT=Count(1)
From Address
Where State = 'MA'
Group By City
Having Count(1)>5
Gives you a table of cities in MA with more than ...
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...
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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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 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.
–...
Ways to save enums in database
...g.
But if you wanted to really do that, i would create a Suits dimension table:
| Suit | SuitID | Rank | Color |
|------------|--------------|---------------|--------|
| Unknown | 4 | 0 | NULL |
| Heart | 1 | 1 | Red ...
Change a column type from Date to DateTime during ROR migration
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First in your terminal:
rails g migration change_date_format_in_my_table
Then in your migration file:
For Rails >= 3.2:
class ChangeDateFormatInMyTable < ActiveRecord::Migration
def up
change_column :my_table, :my_column, :datetime
end
def down
change_column :my_tabl...
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 ...