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What is the $? (dollar question mark) variable in shell scripting? [duplicate]
...able hold? I can't Google search the answer because they block punctuation characters.
9 Answers
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Select count(*) from multiple tables
How can I select count(*) from two different tables (call them tab1 and tab2 ) having as result:
18 Answers
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Create a unique number with javascript time
...oString(36) + Math.random().toString(36).substr(2) That will give you a 19 character alphanumeric string which is a decent amount of entropy. Albeit half of it is predictable.
– Erik Pukinskis
Jul 30 '17 at 23:32
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How can I strip first X characters from string using sed?
...ave a variable containing the text pid: 1234 and I want to strip first X characters from the line, so only 1234 stays. I have more variables I need to "clean", so I need to cut away X first characters and ${string:5} doesn't work for some reason in my system.
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How do I perform an IF…THEN in an SQL SELECT?
How do I perform an IF...THEN in an SQL SELECT statement?
30 Answers
30
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must appear in the GROUP BY clause or be used in an aggregate function
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Yes, this is a common aggregation problem. Before SQL3 (1999), the selected fields must appear in the GROUP BY clause[*].
To workaround this issue, you must calculate the aggregate in a sub-query and then join it with itself to get the additional columns you'd need to show:
SELECT m.cname...
How to return only the Date from a SQL Server DateTime datatype
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On SQL Server 2008 and higher, you should CONVERT to date:
SELECT CONVERT(date, getdate())
On older versions, you can do the following:
SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, @your_date))
for example
SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE()))
gives me
2008-09-22 00:...
PostgreSQL DISTINCT ON with different ORDER BY
...llowing approaches:
The general solution that should work in most DBMSs:
SELECT t1.* FROM purchases t1
JOIN (
SELECT address_id, max(purchased_at) max_purchased_at
FROM purchases
WHERE product_id = 1
GROUP BY address_id
) t2
ON t1.address_id = t2.address_id AND t1.purchased_at = t2...
How to prevent line break at hyphens on all browsers
...liably than splitting the text to “words” (sequences of non-whitespace characters separated by whitespace) and wrapping each “word” that contains a hyphen inside nobr markup. So input data like bla bla foo-bar bla bla would be turned to bla bla <nobr>foo-bar</nobr> bla bla.
You ...
Why do I get “unresolved external symbol” errors when using templates? [duplicate]
...ings like basic_string<T> you're only ever going to be using it with char or wchar_t so if putting all the implementation in the header is a concern, instantiating it in the cpp is an option. The code is yours to command, not vice-versa.
– shoosh
Oct 31 ...