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What is the correct SQL type to store a .Net Timespan with values > 24:00:00?
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I'd probably convert the ticks into a time object like this: SELECT CAST(DATEADD(MILLISECOND, @Ticks/CAST(10000 AS BIGINT), '1900-01-01') AS TIME). The '1900-01-01' date doesn't matter, of course, it's just the third variable required by ...
A numeric string as array key in PHP
...se a numeric string like "123" as a key in a PHP array, without it being converted to an integer?
11 Answers
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How to correctly implement custom iterators and const_iterators?
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They often forget that iterator must convert to const_iterator but not the other way around. Here is a way to do that:
template<class T, class Tag = void>
class IntrusiveSlistIterator
: public std::iterator<std::forward_iterator_tag, T>
{
typ...
How to write a foreach in SQL Server?
...) IN (''VARCHAR'', ''CHAR'', ''NCHAR'', ''NVARCHAR'') THEN ''('' + REPLACE(CONVERT(VARCHAR(10), max_length), ''-1'', ''MAX'') + '')''
WHEN type_name(system_type_id) IN (''DECIMAL'', ''NUMERIC'') THEN ''('' + CONVERT(VARCHAR(10), precision) + '', '' + CONVERT(VARCHAR(10), scale) + '')''
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How can I convert a string to a number in Perl?
I have a string which holds a decimal value in it and I need to convert that string into a floating point variable. So an example of the string I have is "5.45" and I want a floating point equivalent so I can add .1 to it. I have searched around the internet, but I only see how to convert a string t...
What is the difference between related SQLite data-types like INT, INTEGER, SMALLINT and TINYINT?
...RDBMSes. Everything, internally, is stored as text. Data types are coerced/converted into various storage locations based on affinities (ala data types assigned to columns).
The best thing that I'd recommend you do is to :
Temporarily forget everything you used to know about standalone database d...
How to calculate percentage with a SQL statement
...ase you overflow on the 100 multiplication (e.g. Arithmetic overflow error converting expression to data type int), replace it with division in denominator instead: cast((count(*) / (sum(count(*)) over() / 100)) AS DECIMAL(18, 2)) as Percentage
– Nikita G.
Jan ...
shared_ptr指针被赋值后，原指针会引用清零、自动释放。 - C/C++ - 清泛IT...
shared_ptr指针被赋值后，原指针会引用清零、自动释放。
std::shared_ptr<int> intg;
void foo(std::shared_ptr<int> p)
{
intg = p; // 原指针释放，存储新的智能指针
//*(in...
Pandas DataFrame column to list [duplicate]
...ta in pandas dataframe has both int64 and float64. When I do df.values, it converts the int64 to float64 and the whole array has dtype of float64. Any clues how to deal with this ?
– ShikharDua
Apr 21 '16 at 21:00
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Unable to cast object of type 'System.DBNull' to type 'System.String`
... the first case @Alexander mentions -not matching any row- you can rely on Convert.ToString or any other Convert method if you are fine with the value they return when converting from null: empty string for strings, 0 for numeric values, false for boolean, MinValue for DateTime... msdn.microsoft.com...