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How to see if an object is an array without using reflection?
...d have to check if the object is an instanceof boolean[], byte[], short[], char[], int[], long[], float[], double[], or Object[], if you want to detect all array types.
Also, an int[][] is an instanceof Object[], so depending on how you want to handle nested arrays, it can get complicated.
For the t...
How to find all serial devices (ttyS, ttyUSB, ..) on Linux without opening them?
...t(devicedir.c_str(), &st)==0 && S_ISLNK(st.st_mode)) {
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
// Append '/driver' and return basename of the target
devicedir += "/driver";
if (readlink(devicedir.c_str(), buffer, sizeof(buffer)) >...
How do I change an HTML selected option using JavaScript?
...
document.getElementById('personlist').getElementsByTagName('option')[11].selected = 'selected'
to
document.getElementById('personlist').value=Person_ID;
share
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SQL JOIN and different types of JOINs
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There are relatively new LATERAL JOIN .. SELECT * FROM r1, LATERAL fx(r1)
– Pavel Stehule
Jul 30 '13 at 11:52
13
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C default arguments
...Yes. :-) But not in a way you would expect.
int f1(int arg1, double arg2, char* name, char *opt);
int f2(int arg1, double arg2, char* name)
{
return f1(arg1, arg2, name, "Some option");
}
Unfortunately, C doesn't allow you to overload methods so you'd end up with two different functions. Still...
How do I select an entire row which has the largest ID in the table?
...
You could use a subselect:
SELECT row
FROM table
WHERE id=(
SELECT max(id) FROM table
)
Note that if the value of max(id) is not unique, multiple rows are returned.
If you only want one such row, use @MichaelMior's answer,
SELEC...
How do SQL EXISTS statements work?
... criteria -- this is why it can be faster than IN. Also be aware that the SELECT clause in an EXISTS is ignored - IE:
SELECT s.*
FROM SUPPLIERS s
WHERE EXISTS (SELECT 1/0
FROM ORDERS o
WHERE o.supplier_id = s.supplier_id)
...should hit a division by zero error...
SQL WHERE.. IN clause multiple columns
...a derived table from the subquery, and join table1 to this derived table:
select * from table1 LEFT JOIN
(
Select CM_PLAN_ID, Individual_ID
From CRM_VCM_CURRENT_LEAD_STATUS
Where Lead_Key = :_Lead_Key
) table2
ON
table1.CM_PLAN_ID=table2.CM_PLAN_ID
AND table1.Individual=table2.Indi...
What is “Argument-Dependent Lookup” (aka ADL, or “Koenig Lookup”)?
...eems a bit backwards. I would expect the problem do be when std::swap() is selected rather than the overload specific to the type, A::swap(). The example with std::swap(A::MyClass&, A::MyClass&) seems misleading. since std would never have a specific overload for a user type, I don't think i...
How to set selected value of jquery select2?
This belong to codes prior to select2 version 4
28 Answers
28
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