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PostgreSQL naming conventions
Where can I find a detailed manual about PostgreSQL naming conventions? (table names vs. camel case, sequences, primary keys, constraints, indexes, etc...)
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SQL JOIN vs IN performance?
... faster more often than not.
So if you are only interested in values from table a you can use this query:
SELECT a.*
FROM a
WHERE EXISTS (
SELECT *
FROM b
WHERE b.col = a.col
)
The difference might be huge if col is not indexed, because the db does not have to find al...
How do I keep CSS floats in one line?
... (see question) so below the 100px you have the same issue. Specially with table cells, this stays an issue.
– Sanne
Dec 21 '13 at 18:23
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Postgresql GROUP_CONCAT equivalent?
I have a table and I'd like to pull one row per id with field values concatenated.
7 Answers
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Condition within JOIN or WHERE
...in join improve performance for large amount of data with properly indexed tables.
– Shahdat
Oct 6 '16 at 15:13
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MySQL: Large VARCHAR vs. TEXT?
I've got a messages table in MySQL which records messages between users. Apart from the typical ids and message types (all integer types) I need to save the actual message text as either VARCHAR or TEXT. I'm setting a front-end limit of 3000 characters which means the messages would never be inserte...
Understanding garbage collection in .NET
...ow. The second duty is however completely invisible. It also generates a table that describes how the local variables inside the method body are used. That table has an entry for each method argument and local variable with two addresses. The address where the variable will first store an object ...
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 ...
How to get innerHTML of DOMNode?
...se;
$dom->formatOutput = true;
$dom->load($html_string);
$domTables = $dom->getElementsByTagName("table");
// Iterate over DOMNodeList (Implements Traversable)
foreach ($domTables as $table)
{
echo DOMinnerHTML($table);
}
?>
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GROUP BY with MAX(DATE) [duplicate]
...ng to list the latest destination (MAX departure time) for each train in a table, for example :
6 Answers
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