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How to sum a variable by group
...as "model Frequency by Category" or "Frequency depending on Category". Not all languages use a special operator to define a symbolic function, as done in R here. Perhaps with that "natural-language interpretation" of the tilde operator, it becomes more meaningful (and even intuitive). I personally f...
Nested select statement in SQL Server
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"Right, I'm an idiot! Thanks, will accept once allowed." Nah. Just ignorant. Like all of us.
– Lucio Mollinedo
Aug 21 '18 at 14:49
2
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PostgreSQL delete all content
Hello I want to delete all data in my postgresql tables, but not the table itself.
How could I do this?
3 Answers
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Discard all and get clean copy of latest revision?
...g update -r MY_BRANCH -C
The -C flag tells the update command to discard all local changes before updating.
However, this might still leave untracked files in your repository. It sounds like you want to get rid of those as well, so I would use the purge extension for that:
hg pull
hg update -r M...
Generate all permutations of a list without adjacent equal elements
...is greedy algorithm returns optimal solutions, by the following logic. We call a prefix (partial solution) safe if it extends to an optimal solution. Clearly the empty prefix is safe, and if a safe prefix is a whole solution then that solution is optimal. It suffices to show inductively that each gr...
How to list all the available keyspaces in Cassandra?
...y the schema_keyspaces table in the system keyspace. There's also a table called schema_columnfamilies which contains information about all tables.
The DESCRIBE and SHOW commands only work in cqlsh and cassandra-cli.
share
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How can I apply a border only inside a table?
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jsFiddle Demo
The problem is that you are setting a 'full border' around all the cells, which make it appear as if you have a border around the entire table.
Cheers.
EDIT: A little more info on those pseudo-classes can be found on quirksmode, and, as to be expected, you are pretty much S.O.L. in...
Android Studio - local path doesn't exist
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I originally saw this error after upgrading from 0.2.13 to 0.3. These instructions have been updated for the release of Android Studio 0.5.2. These are the steps I completed to resolve the issue.
1.In build.gradle make sure gradle i...
Deleting an element from an array in PHP
...ndex the keys you can use \array_values() after unset() which will convert all keys to numerical enumerated keys starting from 0.
Code
<?php
$array = [0 => "a", 1 => "b", 2 => "c"];
unset($array[1]);
//↑ Key which you want to delete
?>
Output
[
[0] =&g...
Drop all the tables, stored procedures, triggers, constraints and all the dependencies in one sql st
...ere any way in which I can clean a database in SQl Server 2005 by dropping all the tables and deleting stored procedures, triggers, constraints and all the dependencies in one SQL statement?
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