Tutorial by Topics: i

An Activity represents a single screen with a user interface(UI). An Android App may have more than one Activity, for example, An email App can have one activity to list all the emails, another activity to show email contents, yet another activity to compose new email. All the activities in an App w...

CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition; ///Simple create view syntax CREATE [OR REPLACE] [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}] [DEFINER = { user | CURRENT_USER }] [SQL SECURITY { DEFINER | INVOKER }] VIEW view_name [(column_list)] AS sel...

ParametersDetailsDegree of Parallelism (DOP)It is the number of parallel connection/processes which you want your query to open up. It is usually 2, 4, 8, 16 so on.Table NameThe name of the table on which parallel hint will be applied.

a[start:end] # items start through end-1 a[start:] # items start through the rest of the array a[:end] # items from the beginning through end-1 a[start:end:step] # start through not past end, by step a[:] # a copy of the whole array source lst[::-1] gives you a revers...

ActionCable was available for Rails 4.x, and was bundled into Rails 5. It allows easy use of websockets for realtime communication between server and client.

Approach with sealed trait and case objects is preferred because Scala enumeration has a few problems: Enumerations have the same type after erasure. Compiler doesn't complain about “Match is not exhaustive", if case is missed it will fail in runtime scala.MatchError: def isWeekendWith...

Visual Basic 14 is the version of Visual Basic that was shipped as part of Visual Studio 2015. This version was rewritten from scratch in about 1.3 million lines of VB. Many features were added to remove common irritations and to make common coding patterns cleaner. The version number of Visual Ba...

The BigInteger class is used for mathematical operations involving large integers with magnitudes too large for primitive data types. For example 100-factorial is 158 digits - much larger than a long can represent. BigInteger provides analogues to all of Java's primitive integer operators, and all r...

AR is perfect when you need to delete, update or create one or more records sequentially. Its support of dirty attributes (saving only what was really changed) results in optimized UPDATE statements which lifts the load from database significantly and reduces chances for various conflicts connecte...

These classes are reference libraries of methods and properties that do not change state, in one word, immutable. You don't need to create them, you simply use them. Classes and methods such as these are called static classes because they are not created, destroyed, or changed.You can refer to a sta...

Android Marshmallow introduced Runtime Permission model. Permissions are categorized into two categories i.e. Normal and Dangerous Permissions. where dangerous permissions are now granted by the user at run time. From sdk 23 Android requires runtime permissions for permissions on devices runni...