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Validate uniqueness of multiple columns
Is there a rails-way way to validate that an actual record is unique and not just a column? For example, a friendship model / table should not be able to have multiple identical records like:
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How to specify id when uses include in layout xml file
...ml file, I have included other layout xml file (each
with a different android id).
11 Answers
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How can I get last characters of a string
...avascript string method .substr() combined with the .length property.
var id = "ctl03_Tabs1";
var lastFive = id.substr(id.length - 5); // => "Tabs1"
var lastChar = id.substr(id.length - 1); // => "1"
This gets the characters starting at id.length - 5 and, since the second argument for .subs...
How to make a smaller RatingBar?
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The default RatingBar widget is sorta' lame.
The source makes reference to style "?android:attr/ratingBarStyleIndicator" in addition to the "?android:attr/ratingBarStyleSmall" that you're already familiar with. ratingBarStyleIndicator is slightly...
MySQL ON DUPLICATE KEY - last insert id?
...e.html
At the bottom of the page they explain how you can make LAST_INSERT_ID meaningful for updates by passing an expression to that MySQL function.
From the MySQL documentation example:
If a table contains an AUTO_INCREMENT column and INSERT ... UPDATE inserts a row, the LAST_INSERT_ID() func...
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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Javascript - Append HTML to container element without innerHTML
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@kennydelacruz: The OP didn't want to append new HTML to an existing HTML because it destroys and recreates the existing elements. The OP found a solution by creating a new element and append that but they didn't want to add an additional element. I...
Understanding slice notation
...o use slice notation with a sequence that supports it, you must include at least one colon in the square brackets that follow the sequence (which actually implement the __getitem__ method of the sequence, according to the Python data model.)
Slice notation works like this:
sequence[start:stop:step]
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MySQL join with where clause
...N user_category_subscriptions ON
user_category_subscriptions.category_id = categories.category_id
and user_category_subscriptions.user_id =1
See, with an inner join, putting a clause in the join or the where is equivalent. However, with an outer join, they are vastly different.
As a join...
Can I use CASE statement in a JOIN condition?
...T *
FROM sys.indexes i
JOIN sys.partitions p
ON i.index_id = p.index_id
JOIN sys.allocation_units a
ON CASE
WHEN a.type IN (1, 3) AND a.container_id = p.hobt_id THEN 1
WHEN a.type IN (2) AND a.container_id = p.partition_id THEN 1
EL...