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Differences between Perl and PHP [closed]
...rators. In Perl, if you use <, >, ==, !=, <=>, and so on, Perl converts both operands to numbers. If you want to convert as strings instead, you have to use lt, gt, eq, ne, cmp (the respective equivalents of the operators listed previously). Examples where this will really get you:
if (...
How can I represent an infinite number in Python?
...
test > 10000
test > x
Will always be true. Unless of course, as pointed out, x is also infinity or "nan" ("not a number").
Additionally (Python 2.x ONLY), in a comparison to Ellipsis, float(inf) is lesser, e.g:
float('inf') < Ellipsis
would return true.
...
Ignoring a class property in Entity Framework 4.1 Code First
...-First to exclude a particular property
public class Customer
{
public int CustomerID { set; get; }
public string FirstName { set; get; }
public string LastName{ set; get; }
[NotMapped]
public int Age { set; get; }
}
[NotMapped] attribute is included in the System.ComponentMod...
MySQL: Can't create table (errno: 150)
...
From the MySQL - FOREIGN KEY Constraints Documentation:
If you re-create a table that was dropped, it must have a definition that conforms to the foreign key constraints referencing it. It must have the correct column names and types, and it must have index...
What are metaclasses in Python?
... bits and pieces:
def make_hook(f):
"""Decorator to turn 'foo' method into '__foo__'"""
f.is_hook = 1
return f
class MyType(type):
def __new__(mcls, name, bases, attrs):
if name.startswith('None'):
return None
# Go over attributes and see if they shoul...
Static Classes In Java
... []args){
MyStaticClass.setMyStaticMember(5);
System.out.println("Static value: " + MyStaticClass.getMyStaticMember());
System.out.println("Value squared: " + MyStaticClass.squareMyStaticMember());
// MyStaticClass x = new MyStaticClass(); // results in compile time e...
Truncate (not round) decimal places in SQL Server
...eric_expression is to be rounded. length must be an expression of type tinyint, smallint, or int. When length is a positive number, numeric_expression is rounded to the number of decimal positions specified by length. When length is a negative number, numeric_expression is rounded on the left side o...
How to get the current loop index when using Iterator?
...tor iter = list.listIterator();
while (iter.hasNext()) {
System.out.println("index: " + iter.nextIndex() + " value: " + iter.next());
}
Make sure you call the nextIndex BEFORE you actually get the next().
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...
How do I use prepared statements in SQlite in Android?
....getWritableDatabase();
SQLiteStatement stmt = db.compileStatement("INSERT INTO Country (code) VALUES (?)");
stmt.bindString(1, "US");
stmt.executeInsert();
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...
In Postgresql, force unique on combination of two columns
...
CREATE TABLE someTable (
id serial primary key,
col1 int NOT NULL,
col2 int NOT NULL,
unique (col1, col2)
)
autoincrement is not postgresql. You want a serial.
If col1 and col2 make a unique and can't be null then they make a good primary key:
CREATE TABLE someTable...