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Best way to test if a row exists in a MySQL table
... field, a non unique field.
I have made some tests with a TEXT field. Considering the fact that we have a table with 1M entries. 37 entries are equal to 'something':
SELECT * FROM test WHERE texte LIKE '%something%' LIMIT 1 with
mysql_num_rows() : 0.039061069488525s. (FASTER)
SELECT count(*) as ...
The SQL OVER() clause - when and why is it useful?
...itioning By do?
Why can't I make a query with writing Group By SalesOrderID ?
8 Answers
...
Best way to do multiple constructors in PHP
...t() {
// allocate your stuff
}
public static function withID( $id ) {
$instance = new self();
$instance->loadByID( $id );
return $instance;
}
public static function withRow( array $row ) {
$instance = new self();
$instance->fill...
How to reset radiobuttons in jQuery so that none is checked
... but slightly different things. If in this particular case, the advice provide above works if you use 1.6.1+. The above will not work with 1.6.0, if you are using 1.6.0, you should upgrade. If you want the details, keep reading.
Details: When working with straight HTML DOM elements, there are proper...
Populating a ListView using an ArrayList?
My Android app needs to populate the ListView using the data from an ArrayList .
5 Answers
...
Find the index of a dict within a list, by matching the dict's value
... name (using a dictionary), this way get operations would be O(1) time. An idea:
def build_dict(seq, key):
return dict((d[key], dict(d, index=index)) for (index, d) in enumerate(seq))
info_by_name = build_dict(lst, key="name")
tom_info = info_by_name.get("Tom")
# {'index': 1, 'id': '2345', 'na...
Input text dialog Android
...like a good opportunity to use an AlertDialog.
As basic as it seems, Android does not have a built-in dialog to do this (as far as I know). Fortunately, it's just a little extra work on top of creating a standard AlertDialog. You simply need to create an EditText for the user to input data, and s...
SQL join: selecting the last records in a one-to-many relationship
...mmend solving it:
SELECT c.*, p1.*
FROM customer c
JOIN purchase p1 ON (c.id = p1.customer_id)
LEFT OUTER JOIN purchase p2 ON (c.id = p2.customer_id AND
(p1.date < p2.date OR (p1.date = p2.date AND p1.id < p2.id)))
WHERE p2.id IS NULL;
Explanation: given a row p1, there should be no ro...
Return a value if no rows are found in Microsoft tSQL
...E WHEN COUNT(1) > 0 THEN 1 ELSE 0 END AS [Value]
FROM Sites S
WHERE S.Id = @SiteId and S.Status = 1 AND
(S.WebUserId = @WebUserId OR S.AllowUploads = 1)
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SQL Server: SELECT only the rows with MAX(DATE)
...teEntered) FROM yourTable WHERE orderNo = [data].orderNo)
Or...
WHERE
ID = (SELECT TOP 1 ID FROM yourTable WHERE orderNo = [data].orderNo ORDER BY DateEntered DESC)
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