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Switch statement fallthrough in C#?
...ing and during maintenance.
Now, switch could always have been compiled by converting it into the equivalent chain of if-else blocks or similar, but it was designed as allowing compilation into a particular common assembly pattern where one takes a value, computes an offset from it (whether by looki...
Get record counts for all tables in MySQL database
...get the count of rows in all tables in a MySQL database without running a SELECT count() on each table?
19 Answers
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Appending an element to the end of a list in Scala
...stant factors are ignored for asymptotic complexities. I think the List is converted to a ListBuffer, the element is appended, and the ListBuffer converted back (pretty much like String and StringBuilder in Java), but that's just a guess.
– Landei
Aug 9 '13 at ...
Positive Number to Negative Number in JavaScript?
...the ~ bitwise operator.
For example, if you have a = 1000 and you need to convert it to a negative, you could do the following:
a = ~a + 1;
Which would result in a being -1000.
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Create a temporary table in a SELECT statement without a separate CREATE TABLE
Is it possible to create a temporary (session only) table from a select statement without using a create table statement and specifying each column type? I know derived tables are capable of this, but those are super-temporary (statement-only) and I want to re-use.
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selecting unique values from a column
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Use the DISTINCT operator in MySQL:
SELECT DISTINCT(Date) AS Date FROM buy ORDER BY Date DESC;
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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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Passing an array to a query using a WHERE clause
...y external input is sanitized.
$ids = join("','",$galleries);
$sql = "SELECT * FROM galleries WHERE id IN ('$ids')";
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SELECT * FROM X WHERE id IN (…) with Dapper ORM
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Dapper supports this directly. For example...
string sql = "SELECT * FROM SomeTable WHERE id IN @ids"
var results = conn.Query(sql, new { ids = new[] { 1, 2, 3, 4, 5 }});
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Referring to a Column Alias in a WHERE Clause
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SELECT
logcount, logUserID, maxlogtm,
DATEDIFF(day, maxlogtm, GETDATE()) AS daysdiff
FROM statslogsummary
WHERE ( DATEDIFF(day, maxlogtm, GETDATE() > 120)
Normally you can't refer to field aliases in the WHERE clau...