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LAST_INSERT_ID() MySQL
...estion that I think must be quite easy. I need to return the LAST INSERTED ID from table1 when I run the following MySql query:
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Random record in ActiveRecord
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I haven't found an ideal way to do this without at least two queries.
The following uses a randomly generated number (up to the current record count) as an offset.
offset = rand(Model.count)
# Rails 4
rand_record = Model.offset(offset).first...
Delete a single record from Entity Framework?
...r table in Entity Framework named employ with a single key column named ID .
15 Answers
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MongoDB, remove object from array
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try..
db.mycollection.update(
{'_id': ObjectId("5150a1199fac0e6910000002")},
{ $pull: { "items" : { id: 23 } } },
false,
true
);
share
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improve this...
generate model using user:references vs user_id:integer
..., you can see that this is the case:
:001 > Micropost
=> Micropost(id: integer, user_id: integer, created_at: datetime, updated_at: datetime)
The second command adds a belongs_to :user relationship in your Micropost model whereas the first does not. When this relationship is specified, Ac...
Mysql error 1452 - Cannot add or update a child row: a foreign key constraint fails
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Quite likely your sourcecodes_tags table contains sourcecode_id values that no longer exists in your sourcecodes table. You have to get rid of those first.
Here's a query that can find those IDs:
SELECT DISTINCT sourcecode_id FROM
sourcecodes_tags tags LEFT JOIN sourcecodes sc ON...
How to get WordPress post featured image URL
...t me know if it works for you.
<?php if (has_post_thumbnail( $post->ID ) ): ?>
<?php $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'single-post-thumbnail' ); ?>
<div id="custom-bg" style="background-image: url('<?php echo $image[0]; ?>')"&g...
Cast an instance of a class to a @protocol in Objective-C
...c is a UIViewController object that conforms to MyProtocol", whereas using id <MyProtocol> translates to "vc is an object of an unknown class that conforms to MyProtocol".
This way the compiler will give you proper type checking on vc - the compiler will only give you a warning if any method ...
Postgresql aggregate array
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Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as marks
FROM student s
LEFT JOIN Grade g ON g.Student_id = s.Id
GROUP BY s.Id
By the way, if you are using Postgres 9.1, you don't need to repeat the columns...
Alternate output format for psql
...on Ubuntu. I have a table with columns c1 through cN . The columns are wide enough that selecting all columns causes a row of query results to wrap multiple times. Consequently, the output is hard to read.
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