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django: BooleanField, how to set the default value to true?
...ou want to dynamically choose at runtime whether or not your field will be selected by default, you can use the initial parameter to the form when you initialize it:
form = MyForm(initial={'my_field':True})
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...
what is the difference between GROUP BY and ORDER BY in sql
... SUM, COUNT, AVG, etc).
TABLE:
ID NAME
1 Peter
2 John
3 Greg
4 Peter
SELECT *
FROM TABLE
ORDER BY NAME
=
3 Greg
2 John
1 Peter
4 Peter
SELECT Count(ID), NAME
FROM TABLE
GROUP BY NAME
=
1 Greg
1 John
2 Peter
SELECT NAME
FROM TABLE
GROUP BY NAME
HAVING Count(ID) > 1
=
Peter
...
Check if a row exists, otherwise insert
...
I assume a single row for each flight? If so:
IF EXISTS (SELECT * FROM Bookings WHERE FLightID = @Id)
BEGIN
--UPDATE HERE
END
ELSE
BEGIN
-- INSERT HERE
END
I assume what I said, as your way of doing things can overbook a flight, as it will insert a new row when there are 1...
Firefox ignores option selected=“selected”
If you change a dropdown and refresh the page, Firefox seems to ignore the selected attribute.
20 Answers
...
The order of elements in Dictionary
...r elements in key-order then they should to dict.Keys.OrderBy( k => k ).Select( k => dict[k] ) instead (at the cost of O(n) space and O( n log n ) time) for the OrderBy() (which will need to buffer the entire keys collection in an internal list).
– Dai
Oc...
Postgres DB Size Command
..."pg_datbase" system table. Just apply the function to the names, as below.
select t1.datname AS db_name,
pg_size_pretty(pg_database_size(t1.datname)) as db_size
from pg_database t1
order by pg_database_size(t1.datname) desc;
If you intend the output to be consumed by a machine instead of a...
MySQL Insert Where query
...INSERT INTO Users(weight, desiredWeight)
VALUES (160,145)
INSERT using a SELECT statement
INSERT INTO Users(weight, desiredWeight)
SELECT weight, desiredWeight
FROM AnotherTable
WHERE id = 1
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How do you run NUnit tests from Jenkins?
...y]$files = get-childitem $sourceDirectory -include $fileFilters -recurse | select -expand FullName | where {$_ -like $filterText}
foreach ($file in $files)
{
$cFiles = $cFiles + $file + " "
}
# set all arguments and execute the unit console
$argumentList = @("$cFiles", "/framework:net-4.5", "/...
Should MySQL have its timezone set to UTC?
...the timezone will not change the stored datetime or
timestamp, but it will select a different datetime from
timestamp columns
Warning! UTC has leap seconds, these look like '2012-06-30 23:59:60' and can
be added randomly, with 6 months prior notice, due to the slowing of
the earths rotation
GMT con...
How to remove all MySQL tables from the command-line without DROP database permissions? [duplicate]
...tatements to execute it:
SET FOREIGN_KEY_CHECKS = 0;
SET @tables = NULL;
SELECT GROUP_CONCAT('`', table_schema, '`.`', table_name, '`') INTO @tables
FROM information_schema.tables
WHERE table_schema = 'database_name'; -- specify DB name here.
SET @tables = CONCAT('DROP TABLE ', @tables);
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