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How to list the tables in a SQLite database file that was opened with ATTACH?
....schema tablename
Print the entire table:
SELECT * FROM tablename;
List all of the available SQLite prompt commands:
.help
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Setting onClickListener for the Drawable right of an EditText [duplicate]
... y = actionY;
/** Creates square from the smallest value */
if (x < y) {
y = x;
}
}
if (bounds.contains(x, y) && clickListener != null) {
cli...
Removing packages installed with go get
... I needed to set my GOPATH otherwise that package sullies my root Go install (I would much prefer to keep my Go install clean and separate core from custom). How do I remove packages installed previously?
...
How do I parse a string to a float or int?
...
Python method to check if a string is a float:
def is_float(value):
try:
float(value)
return True
except:
return False
A longer and more accurate name for this function could be: is_convertible_to_float(value)
What is, and is not a float in Python may surpris...
PostgreSQL: insert from another table
...
Just supply literal values in the SELECT:
INSERT INTO TABLE1 (id, col_1, col_2, col_3)
SELECT id, 'data1', 'data2', 'data3'
FROM TABLE2
WHERE col_a = 'something';
A select list can contain any value expression:
But the expressions in the select list do not have to reference any columns i...
how to clear the screen in python [duplicate]
... To avoid the 0 (system's return value) being shown, use absolutely_unused_variable = os.system("cls") or absolutely_unused_variable = os.system("clear")
– Shiva
Jul 4 '15 at 8:01
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CMap用法 - C/C++ - 清泛网 - 专注C/C++及内核技术
...的效率。CMap就是对Hash表的一种实现。先上实例：
int _tmain(int argc, char* argv[])
{
//定义
typedef CMap<int, int, CString, CString> CMapInt;
CMapInt map;
//添加key，val
map.SetAt(1, "str1");
map.SetAt(2, "str2");
map.SetAt(3, "str3");
map.SetAt(1, "s...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘c...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘class Derived*’ (source type is not polymorphic)在将父类型转换为子类型时,可以使用static_cast和dynamic_cast.如果使用dynamic_cast,它要求父类必须为多态的,即要求至少有一个虚函数,因此....
MFC的DDX和DDV技巧 - C/C++ - 清泛网 - 专注C/C++及内核技术
...件关系的成员变量的声明，代码：
// Dialog Data
//{{AFX_DATA(CMyDlg)
enum { IDD = IDD_DIALOG5 };
int m_edit;
//}}AFX_DATA
２． 在 .CPP文件中的类构造函数告终代码处，增加数据成员变量的一些初始化代码
CMyDlg::CMyDlg(CWnd* pParent )
...
Scatterplot with too many points
...;- data.frame(x = rnorm(5000),y=rnorm(5000))
ggplot(df,aes(x=x,y=y)) + geom_point(alpha = 0.3)
Another convenient way to deal with this is (and probably more appropriate for the number of points you have) is hexagonal binning:
ggplot(df,aes(x=x,y=y)) + stat_binhex()
And there is also regula...