Tutorial by Examples: table

A Table View is a list of rows that can be selected. Each row is populated from a data source. This example creates a simple table view in which each row is a single line of text. Add a UITableView to your Storyboard Although there are a number of ways to create a UITableView, one of the easiest...

The CREATE TABLE statement is used to create a table in a MySQL database. CREATE TABLE Person ( `PersonID` INTEGER NOT NULL PRIMARY KEY, `LastName` VARCHAR(80), `FirstName` VARCHAR(80), `Address` TEXT, `City` VARCHAR(100) ) Engine=InnoDB; Ev...

CREATE TABLE Person ( PersonID INT UNSIGNED NOT NULL, LastName VARCHAR(66) NOT NULL, FirstName VARCHAR(66), Address VARCHAR(255), City VARCHAR(66), PRIMARY KEY (PersonID) ); A primary key is a NOT NULL single or a multi-column identifier whic...

CREATE TABLE Account ( AccountID INT UNSIGNED NOT NULL, AccountNo INT UNSIGNED NOT NULL, PersonID INT UNSIGNED, PRIMARY KEY (AccountID), FOREIGN KEY (PersonID) REFERENCES Person (PersonID) ) ENGINE=InnoDB; Foreign key: A Foreign Key (FK) is either a single col...

A table can be replicated as follows: CREATE TABLE ClonedPersons LIKE Persons; The new table will have exactly the same structure as the original table, including indexes and column attributes. As well as manually creating a table, it is also possible to create table by selecting data from anot...

A data.table is an enhanced version of the data.frame class from base R. As such, its class() attribute is the vector "data.table" "data.frame" and functions that work on a data.frame will also work with a data.table. There are many ways to create, load or coerce to a data.table....

One of the main differences between lists and tuples in Python is that tuples are immutable, that is, one cannot add or modify items once the tuple is initialized. For example: >>> t = (1, 4, 9) >>> t[0] = 2 Traceback (most recent call last): File "<stdin>", l...

To create a pure JSON table you need to provide a single field with the type JSONB: CREATE TABLE mytable (data JSONB NOT NULL); You should also create a basic index: CREATE INDEX mytable_idx ON mytable USING gin (data jsonb_path_ops); At this point you can insert data in to the table and que...

The table-layout property changes the algorithm that is used for the layout of a table. Below an example of two tables both set to width: 150px: The table on the left has table-layout: auto while the one on the right has table-layout: fixed. The former is wider than the specified width (210px in...

Arrays can have the allocatable attribute: ! One dimensional allocatable array integer, dimension(:), allocatable :: foo ! Two dimensional allocatable array real, dimension(:,:), allocatable :: bar This declares the variable but does not allocate any space for it. ! We can specify the bounds...

To create a join table between students and courses, run the command: $ rails g migration CreateJoinTableStudentCourse student course This will generate the following migration: class CreateJoinTableStudentCourse < ActiveRecord::Migration[5.0] def change create_join_table :students, ...

To add a new column name to the users table, run the command: rails generate migration AddNameToUsers name This generates the following migration: class AddNameToUsers < ActiveRecord::Migration[5.0] def change add_column :users, :name, :string end end When the migration name i...

To remove existing column name from users table, run the command: rails generate migration RemoveNameFromUsers name:string This will generate the following migration: class RemoveNameFromUsers < ActiveRecord::Migration[5.0] def change remove_column :users, :name, :string end end ...

To add a reference to a team to the users table, run this command: $ rails generate migration AddTeamRefToUsers team:references This generates the following migration: class AddTeamRefToUsers < ActiveRecord::Migration[5.0] def change add_reference :users, :team, foreign_key: true ...

To create a new users table with the columns name and salary, run the command: rails generate migration CreateUsers name:string salary:decimal This will generate the following migration: class CreateUsers < ActiveRecord::Migration[5.0] def change create_table :users do |t| t.s...

To add multiple columns to a table, separate field:type pairs with spaces when using rails generate migration command. The general syntax is: rails generate migration NAME [field[:type][:index] field[:type][:index]] [options] For example, the following will add name, salary and email fields to ...

Create a simple table create table MY_table ( what varchar2(10), who varchar2(10), mark varchar2(10) ); Insert values (you can omit target columns if you provide values for all columns) insert into my_table (what, who, mark) values ('Hello', 'world', '!' ); insert into my_table ...

The data.table package provides a convenient way to group by runs in data. Consider the following example data: library(data.table) (DT <- data.table(x = c(1, 1, 2, 2, 2, 1), y = 1:6)) # x y # 1: 1 1 # 2: 1 2 # 3: 2 3 # 4: 2 4 # 5: 2 5 # 6: 1 6 The variable x has three runs: a run ...

NSArray *myColors = [NSArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil]; // Convert myColors to mutable NSMutableArray *myColorsMutable = [myColors mutableCopy];

This example of the Sortable using a Placeholder is common usage. Sortable is applied to a group of DOM elements, allowing the user to move items around in the list via Drag'n Drop style actions. <!doctype html> <html lang="en"> <head> <meta charset="utf-8&q...