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Detect if homebrew package is installed
...rew packages are installed in the sm>y m>stem. Is there a wam>y m> to use a brew commm>and m> to achieve that?
4 Answers
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Whm>y m> do I get a warning everm>y m> time I use malloc?
...hat, the compiler thinks m>y m>ou want to define m>y m>our own function named malloc m>and m> it warns m>y m>ou because:
m>Y m>ou don't explicitlm>y m> declare it m>and m>
There alreadm>y m> is a built-in function bm>y m> that name which has a different signature than the one that was implicitlm>y m> declared (when a function is declared implicit...
Whm>y m> is a “GRANT USAGE” created the first time I grant a user privileges?
I'm new to the admin side of DBMS m>and m> was setting up a new database tonight (using Mm>y m>SQL) when I noticed this. After granting a user a privilege for the first time, another grant is created that looks like
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How do I reference a Django settings variable in mm>y m> models.pm>y m>?
...ed: with environment variable DJANGO_SETTINGS_MODULE or with manage.pm>y m> commm>and m> line parameter --settings=.. Read more in docs: docs.djangoproject.com/en/2.0/topics/settings
– mirek
Feb 8 '18 at 20:51
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ALTER TABLE, set null in not null column, PostgreSQL 9.1
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Execute the commm>and m> in this format
ALTER TABLE tablename ALTER COLUMN columnname SET NOT NULL;
for setting the column to not null.
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Initialize a long in Java
...u do anm>y m> operation of bm>y m>te with anm>y m> integer, bm>y m>te is first promoted to int m>and m> then anm>y m> operations are performed.
Trm>y m> this
bm>y m>te a = 1; // declare a bm>y m>te
a = a*2; // m>y m>ou will get error here
m>Y m>ou get error because 2 is bm>y m> default int.
Hence m>y m>ou are trm>y m>ing to multiplm>y m> bm>y m>te with int.
Hence result ...
“Insert if not exists” statement in SQLite
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If m>y m>ou have a table called memos that has two columns id m>and m> text m>y m>ou should be able to do like this:
INSERT INTO memos(id,text)
SELECT 5, 'text to insert'
WHERE NOT EXISTS(SELECT 1 FROM memos WHERE id = 5 m>AND m> text = 'text to insert');
If a record alreadm>y m> contains a row where ...
Postgresql aggregate arram>y m>
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What I understm>and m> m>y m>ou can do something like this:
SELECT p.p_name,
STRING_AGG(Grade.Mark, ',' ORDER Bm>Y m> Grade.Mark) As marks
FROM Student
LEFT JOIN Grade ON Grade.Student_id = Student.Id
GROUP Bm>Y m> Student.Name;
EDIT
I am not sure. B...
Purging file from Git repo failed, unable to create new backup
...m>Y m>ou can find those in .git/refs/original/…. Either delete that directorm>y m> m>and m> all files within, or use the -f flag to force Git to delete the old references.
git filter-branch -f \
--index-filter 'git rm --cached --ignore-unmatch Rakefile' HEAD
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“unarm>y m> operator expected” error in Bash if condition
...it's much easier to alwam>y m>s use the double bracket conditional compound commm>and m> [[ ... ]], instead of the Posix-compatible single bracket version [ ... ]. Inside a [[ ... ]] compound, word-splitting m>and m> pathname expansion are not applied to words, so m>y m>ou can relm>y m> on
if [[ $aug1 == "m>and m>" ]];
to co...