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Delete column from SQLite table
... TRANSACTION;
CREATE TEMPORARY TABLE t1_backup(a,b);
INSERT INTO t1_backup SELECT a,b FROM t1;
DROP TABLE t1;
CREATE TABLE t1(a,b);
INSERT INTO t1 SELECT a,b FROM t1_backup;
DROP TABLE t1_backup;
COMMIT;
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Rename a class in Xcode: Refactor… is grayed out (disabled). Why?
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Select the class's symbol in its header file - i.e. the bit just after @interface. Then the refactoring stuff should be enabled.
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What is this operator in MySQL?
...d <> both give UNKNOWN with NULL on either side of the expression.)
SELECT *
FROM table
WHERE YourColumn IS NOT NULL;
can also negate the null safe equality operator but this is not standard SQL.
SELECT *
FROM table
WHERE NOT (YourColumn <=> NULL);
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Notepad++ Multi editing
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Yes: simply press and hold the Alt key, click and drag to select the lines whose columns you wish to edit, and begin typing.
You can also go to Settings > Preferences..., and in the Editing tab, turn on multi-editing, to enable selection of multiple separate regions or columns o...
Execute stored procedure with an Output parameter?
...s to right-click on the procedure in Sql Server Management Studio(SSMS),
select execute stored procedure...
and add values for the input parameters as prompted.
SSMS will then generate the code to run the proc in a new query window, and execute it for you. You can study the generated code to se...
Database Design for Tagging
... to rebuilt every time a question has a tag added or removed. A query like select * from question q inner join question_has_tag qt where tag_id in (select tag_id from tags where (what we want) minus select tag_id from tags where (what we don't) should be fine and scale out assuming the right b-tree ...
How to remove application from app listings on Android Developer Console
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Select Store Presense then Pricing Distribution and select Unpublish from App Availability.
Google's help for this is here: https://support.google.com/googleplay/android-developer/answer/113476#unpublish (as of Feb-2020)
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Making macOS Installer Packages which are Developer ID ready
...gbuild
persisting obsolescence
Known Issues and Workarounds
Destination Select Pane
The user is presented with the destination select option with only a single choice - "Install for all users of this computer". The option appears visually selected, but the user needs to click on it in order to p...
Multiple “order by” in LINQ
...ow in _db.Movies
orderby row.Category, row.Name
select row;
[EDIT to address comment] To control the sort order, use the keywords ascending (which is the default and therefore not particularly useful) or descending, like so:
var movies = from row in _db.Movies
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What is LINQ and what does it do? [closed]
...;string> result =
from c in myCustomers
where c.Name.StartsWith("B")
select c.Name;
Lambda Expressions - This is a shorthand for specifying a method. The C# compiler will translate each into either an anonymous method or a true System.Linq.Expressions.Expression. You really need to understand...