What is SQL

SQL

SQL (Structure Query Language) is a non-procedural language. SQL are used for access and manipulate data in databases. SQL is an ANSI (American National Standards Institute) standard language.

Why need of SQL

SQL is required for perform following operation on database

To create new databases, tables.
To insert any records in database
To update records in database
To delete records from database
To retrieve data from database

Features of SQL

SQL is not a case sensitive language.
Every commands in SQL should ends with semicolon(;).
SQL can also called as sequel (SEQUEL).
It is an ANSI (American National Standards Institute) standard language.

Limitation of SQL

SQL does not support looping and condition statements etc.
In SQL you can not execute more than one statement at a time, so it increase the network traffic.
SQL always gives system defined error message, when user perform any wrong transaction.
SQL does not support the code re-usability, it means you need to write insert, delete, update, select command each and every time.
SQL does not support procedure language features such as code re-usability and molecularity and some other features of oops.

To Overcome all these above limitation we use PL/SQL.

Comments

SQL Commands

SQL Commands SQL Commands are mainly classified into four types, which are DDL command, DML command, TCL command and DCL command. SQL is mainly divided into four sub language Data Definition Language(DDL) Data Manipulation Language(DML) Transaction Control Language(TCL) Data Control Language(DCL) Only for remember You can easily remember all these SQL command like below; DDL Commands: "dr. cat" d-drop, r-remane, c-create, a-alter, t-truncate. DML Commands: "sudi". s-select, u-update, d-delete, i-insert. TCL Commands: These commands are related to transaction, commands are: Commit, Rollback, Savepoint

Python - Function

Define Function in Python Function is block of codes. Python provide built-in and user define both types of function. Built-in function User defined function Built-in function This type of functions are pre-defined, you can directly use in your program. For example print function is used for display message on screen or console. Print hello world in python a = "Hello World!" print a User defined function This type of functions are defined by programmer. According to your requirement you can defined you function name and it's functionality. In python you can define any function by using def keyword. Syntax for define function in python def function_name ( parameter ) function body Define function in python def my_function(fname): print(fname + " Refsnes") my_function ("Emil") my_function ("Tobias") my_function ("Linus") Output Emil Refsnes Tobias Refsnes Linus Refsnes Explanation

Frames

A framed page is actually made up of multiple HTML pages. There is one HTML document that describes how to break up the single browser window into multiple windowpanes. Each windowpane is filled with an HTML document. Frame Page Architecture § A <FRAMESET> element is placed in the html document before the <BODY> element. The <FRAMESET> describes the amount of screen real estate given to each windowpane by dividing the screen into ROWS or COLS . § The <FRAMESET> will then contain <FRAME> elements, one per division of the browser window. § Note: Because there is no BODY container, FRAMESET pages can't have background images and background colors associated with them. Frame Page Architecture <HTML> <HEAD> <TITLE> Framed Page </TITLE> <FRAMeSET COLS=“23%,77%”> <FRAME SRC=“Doc1.html”> <FRAME SRC=“Doc2.html”> </FRAMeSET > </HEAD> </HTML>

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