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What is cardinality in MySQL?
...ow cardinality column with only 2 possible values as the index will not be selective enough to be used.
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Creating Unicode character from its number
I want to display a Unicode character in Java. If I do this, it works just fine:
13 Answers
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urlencode vs rawurlencode?
...ction.rawurlencode.php)
Returns a string in which all non-alphanumeric characters except -_.~ have been replaced with a percent (%) sign followed by two hex digits. This is the encoding described in » RFC 3986 for protecting literal characters from being interpreted as special URL delimiters, a...
Take a char input from the Scanner
I am trying to find a way to take a char input from the keyboard.
22 Answers
22
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How can mixed data types (int, float, char, etc) be stored in an array?
...minated union, aka tagged union.
struct {
enum { is_int, is_float, is_char } type;
union {
int ival;
float fval;
char cval;
} val;
} my_array[10];
The type member is used to hold the choice of which member of the union is should be used for each array element. ...
Is there a way to specify how many characters of a string to print out using printf()?
Is there a way to specify how many characters of a string to print out (similar to decimal places in int s)?
8 Answers
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Fetch the row which has the Max value for a column
... multiple rows for the userid where the maximum date is on multiple rows.
select userid,
my_date,
...
from
(
select userid,
my_date,
...
max(my_date) over (partition by userid) max_my_date
from users
)
where my_date = max_my_date
"Analytic functions rock"
Edi...
Conveniently Declaring Compile-Time Strings in C++
...y cumbersome, as the string needs to be declared as a variadic sequence of characters, e.g.
15 Answers
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convert a char* to std::string
...g to store data retrieved by fgets() . To do this I need to convert the char* return value from fgets() into an std::string to store in an array. How can this be done?
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uint8_t can't be printed with cout
...
It doesn't really print a blank, but most probably the ASCII character with value 5, which is non-printable (or invisible). There's a number of invisible ASCII character codes, most of them below value 32, which is the blank actually.
You have to convert aa to unsigned int to output t...