SQL

Photo by Irvan Smith on Unsplash
Photo by Irvan Smith on Unsplash

Introduction to Java

Java is a high-level, general-purpose, compiled programming language. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of computer architecture.  It is intended to let application developers “write once, run anywhere” (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation.

History

Java was originally developed by James Gosling at Sun Microsystems (which has since been acquired by Oracle Corporation) and released in 1995 as a core component of Sun Microsystems’ Java platform. The language derives much of its syntax from C and C++, but it has fewer low-level facilities than either of them. The original and reference implementation Java compilers, virtual machines, and class libraries were originally released by Sun under proprietary licenses. As of May 2007, in compliance with the specifications of the Java Community Process, Sun relicensed most of its Java technologies under the GNU General Public License.

Java Resources

  • Getting Started: Download
  • Beginner Tutorials
  • Intermediate Tutorials
  • Advanced Tutorials
  • Good Beginner Blog
  • Good Intermediate Blog
  • Good Advanced Blog
  • Official Documentation

Quick Reference – Java

Here is a quick reference for the basics of C#…

Hello World in Java

using System; 
class Program { 
    static void Main(string[] args) { 
        Console.WriteLine("Hello, world!"); 
    } 
}

Java: Basic Syntax

Variables & Data Types

Branching

Arrays

Lists

Dictionaries

Loops (ForEach, For)

Java: Object-Oriented Syntax

Classes

Objects

Methods

Constructors

SQL (Structured Query Language) is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS). In comparison to older read/write APIs like ISAM or VSAM, SQL offers two main advantages: first, it introduced the concept of accessing many records with one single command; and second, it eliminates the need to specify how to reach a record, e.g. with or without an index.

Originally based upon relational algebra and tuple relational calculus, SQL consists of many types of statements,[9] which may be informally classed as sublanguages, commonly: a data query language (DQL),[a] a data definition language (DDL),[b] a data control language (DCL), and a data manipulation language (DML)[c].[10] The scope of SQL includes data query, data manipulation (insert, update and delete), data definition (schema creation and modification), and data access control. Although SQL is often described as, and to a great extent is, a declarative language (4GL), it also includes procedural elements.

SQL was one of the first commercial languages for Edgar F. Codd’s relational model, as described in his influential 1970 paper, “A Relational Model of Data for Large Shared Data Banks”.[11] Despite not entirely adhering to the relational model as described by Codd, it became the most widely used database language.[12][13]

SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987.[14] Since then, the standard has been revised to include a larger set of features. Despite the existence of such standards, most SQL code is not completely portable among different database systems without adjustments.

About the author

WCD

Karen Freeman-Smith lives near Portland, OR with her partner, two grown children (in and out of the basement), and a cat named Shiva. Karen maintains two personal websites as well as several topical websites about: Programming, Web Development, Foreign Languages, International Students, Fiction Writing, and Typing.
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