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Let's take a sample class. class Book: def __init__(self, title, author): self.title = title self.author = author book1 = Book(title="Right Ho, Jeeves", author="P.G. Wodehouse") In Python you can access the attribute title of the class using the dot ...

PDO is a universal database connection command in PHP, it support 12 different database type e.g MySQL, MongoDB, NoSQL. A big bonus about PDO is that it calculate your code to support the database type, so you don't need to make any chance when moving over to another database system. Summary PDO...

For example, types for SI units have been standardized in the F# core library, in Microsoft.FSharp.Data.UnitSystems.SI. Open the appropriate sub-namespace, UnitNames or UnitSymbols, to use them. Or, if only a few SI units are required, they can be imported with type aliases: /// Seconds, the SI uni...

class User { String name int age } def users = [ new User(name: "Bob", age: 20), new User(name: "Tom", age: 50), new User(name: "Bill", age: 45) ] // sort by age users.sort { a, b -> a.age <=> b.age }

The volatile modifier is used in multi threaded programming. If you declare a field as volatile it is a signal to threads that they must read the most recent value, not a locally cached one. Furthermore, volatile reads and writes are guaranteed to be atomic (access to a non-volatile long or double i...

Because generating documentation is based on markdown, you have to do 2 things : 1/ Write your doctest and make your doctest examples clear to improve readability (It is better to give a headline, like "examples" or "tests"). When you write your tests, do not forget to give 4 s...

Once you've installed the .NET CLI tools, you can create a new project with the following command: dotnet new --lang f# This creates a command line program.

Specifies a numeric minimum and maximum range for a property using System.ComponentModel.DataAnnotations; public partial class Enrollment { public int EnrollmentID { get; set; } [Range(0, 4)] public Nullable<decimal> Grade { get; set; } } If we try to insert/upd...

Specifies how the database generates values for the property. There are three possible values: None specifies that the values are not generated by the database. Identity specifies that the column is an identity column, which is typically used for integer primary keys. Computed specifies that th...

By Code-First convention, Entity Framework creates a column for every public property that is of a supported data type and has both a getter and a setter. [NotMapped] annotation must be applied to any properties that we do NOT want a column in a database table for. An example of a property that we ...

[Table("People")] public class Person { public int PersonID { get; set; } public string PersonName { get; set; } } Tells Entity Framework to use a specific table name instead of generating one (i.e. Person or Persons) We can also specify a schema for the table using [T...

public class Person { public int PersonID { get; set; } [Column("NameOfPerson")] public string PersonName { get; set; } } Tells Entity Framework to use a specific column name instead using the name of the property. You can also specify the database data type a...

public class Person { public int PersonID { get; set; } public string PersonName { get; set; } [Index] public int Age { get; set; } } Creates a database index for a column or set of columns. [Index("IX_Person_Age")] public int Age { get; set; } This creates ...

MATCH (n) WHERE n.some_attribute = "some identifier" SET n.other_attribute = "a new value"

I create a file called database-servlet.xml somewhere on the classpath. Initially your config file will look like this: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/...

One of the great things about Linq is that it is so easy to extend. You just need to create an extension method whose argument is IEnumerable<T>. public namespace MyNamespace { public static class LinqExtensions { public static IEnumerable<List<T>> Batch<T&...

Active Patterns can be used to make calling some .NET API's feel more natural, particularly those that use an output parameter to return more than just the function return value. For example, you'd normally call the System.Int32.TryParse method as follows: let couldParse, parsedInt = System.Int32....

One of the easiest examples of using shared services is when we want to store some data from a given page of our application, and then get that data again but from another page. One option could be to send that data as a parameter (for instance, if one page calls the other one) but if we want to us...

The following sqoop command will be used to import the data from RDBMS table into HBase table, if the table does not exists in HBase it will create a new table and import the data into this table sqoop import \ --query 'select emp_id, emp_name, emp_sal from employee where $CONDITIONS' \ ...

The attribute status_code contains the status code of the response good_req = requests.get('https://api.github.com/events') code_200 = good_req.status_code notfound_req = requests.get('https://api.github.com/not_found') code_404 = notfound_req.status_code requests.codes.__dict__ will provid...