Tutorial by Examples: composite

You can create widgets composed of multiple widgets using MultiWidget. from datetime import date from django.forms.widgets import MultiWidget, Select from django.utils.dates import MONTHS class SelectMonthDateWidget(MultiWidget): """This widget allows the user to fill in ...

This will create a composite index of both keys, mystring and mydatetime and speed up queries with both columns in the WHERE clause. CREATE INDEX idx_mycol_myothercol ON my_table(mycol, myothercol) Note: The order is important! If the search query does not include both columns in the WHERE claus...

The Composite pattern is a design pattern that allows to treat a group of objects as a single instance of an object. It is one of the Gang of Four's structural design patterns. Example below demonstrate how Composite can be used to log to multiple places using single Log invocation. This approach a...

By using the .HasKey() method, a set of properties can be explicitly configured as the composite primary key of the entity. using System.Data.Entity; // .. public class PersonContext : DbContext { // .. protected override void OnModelCreating(DbModelBuilder modelBuilder) {...

-- composite key - using two or more existing columns within a table to create a primary key create table person ( firstName varchar(100) not null, lastName varchar(100) not null, dob DateTime not null, ssn varchar(9) not null, primary key (firstName, lastName, dob) )

Clear the canvas using compositing operation. This will clear the canvas independent of transforms but is not as fast as clearRect(). ctx.globalCompositeOperation = 'copy'; anything drawn next will clear previous content.

In many situations, a composite index performs better than an index with a single column. To build an optimal composite index, populate it with columns in this order. = column(s) from the WHERE clause first. (eg, INDEX(a,b,...) for WHERE a=12 AND b='xyz' ...) IN column(s); the optimizer may be...

The Sales Orders screen (SO.30.10.00) is a perfect example of a data entry form with a composite primary key. The primary key on the Sales Orders screen is composed by the Order Type and the Order Number: The recommended 2-step strategy to export data from the Sales Orders screen or any other dat...

When creating a model for a table that has a composite primary key, additional work is required on the Object for the model Entity to respect those constraints. The following example SQL table and Entity demonstrates the structure to store a review left by a customer for an item in an online store....