DROP TABLE Statement in SQL

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DROP TABLE Statement in SQL

SQL DROP TABLE statement is used to remove table in a database. When you use the SQL DROP TABLE statement to remove a table, the database engine deletes all objects associated to that table including data, table structure, indexes, constraints, triggers and maybe privileges.

DROP TABLE Statement

The Drop Table command of SQL lets you drop a table from the database.

That is, to drop a table items, you need to write : The syntax for using a Drop Table command is :

DROP TABLE items ;

Once this…

SQL ALTER TABLE Command

The Alter Table command is used to change definitions of existing tables. Usually, it can add columns to table. Sometimes it can delete columns (depending on privileges) or change their sizes.

In short we can say,

The ALTER TABLE statement is used to add, delete, or modify columns in an existing table.

The ALTER TABLE statement is also used to add and drop various constraints on an existing table.

1. ALTER TABLE — ADD Column

To add a column in a table, use the following syntax:

Syntax :

ALTER TABLE table_name 
ADD column_name datatype;

For instance, to add a new column tel_number of type integer in table Student.

…

Best CBSE Employment And Unemployment
Chapter 10

Employment And Unemployment

1. Some Basic Concepts Unemployment :

It refers to a situation when people are willing to work at the existing wage rate, and are able to work, but are not getting work.

Worker :

A worker is an individual who is engaged in some production activity.
workers are classified as :

Self -employed and Hired Workers

(1) Self -employed Workers :

Chapter 2
Acids, Bases And Salts
Class 10 Notes

Veiw Web Version

Indicators :

Indicators are Substances which indicate the acidic or basic nature of the solution by the colur change.

Natural Indicators :

The indicators obtained from natural sources are called Natural Indicatores.
Examples of some common natural indicators used widely to show acidic or basic character of substances.

(1) Litmus

Litmus solution is a purple dye, which is extracted from lichen, a plant belonging to the division Thallophyta, and is commonly used as an indicator.
An acid turns blue litmus paper red.
An base turns red litmus paper blue.

(2) Turmeric

Tumeric is yellow in colur. Tumeric solution or paper turns reddish brown with basae…

Python Revision Tour II Solutions

Class 12 CS Chapter 2 Python Revision Tour II Solutions

Q 1. What is indexing in context to Python strings ? Why is it also called two-way indexing ?

Ans. In Python strings, each individual character is given a location number, called index and this process is called indexing.
Python allocates indices in two direction :

• in forward direction, the indexes are numbered as 0, 1, 2,…. length-1
• in backward direction, the indexes are numbered as -1, -2. -3…. length.
  This is known as two-way indexing.

Q 2. What is a string slice ? How is it useful ?

Ans. A sub-part or a slice of a string, say s, can be obtained using s[n:m] where n and m are integers. Python returns all the character at indices n, n+1, n+2…m-1 e.g.,
‘Well…

Class 12 CS Chapter 1 Python Revision Tour I

Class 12 CS Chapter 1 Python Revision Tour I Solutions

Q 1. What is the difference between a keyword and an identifier ?

Ans. Keyword is a special word that has a special meaning and purpose. Keywords are reserved and are a few. For example, if, elif, else etc. are keywords.

Identifier is the user-defined name given to part of a program viz. variable, object, function etc. Identifiers are not reserved. These are defined by the user but they can have letters, digits and a symbol underscore. They must begin with either a letter or underscore. For instance, _chk, chess, trial etc. are identifiers in Python.

Q 2. What are literals in Python ? How many types of literals are allowed in Python ?

Ans. Literals mean constants i.e., the data…

File Handling in Python with Examples

1.1 Introduction

File Handling in Python

Most computer programs work with files. This because files help in storing information permanently. Word processors create document files ; Database program create files of information ; Compilers read source files and generate executable files. So, we see, it is the files of that are mostly worded with, inside programs. A file in itself is a bunch of bytes stored on some storage device like hard-disk, thumb-drive etc. Every programming language offers some provision to use and create files through programs. …

Python if…else Statement

THE IF CONDITIONALS

Python if-else Statement
The if conditionals of Python come in multiple forms : plain if conditional, if-else conditional and if-elif conditionals.

1. Plain if Conditional Statement

Python if-else Statement

An if statement tests a particular condition; if the condition evaluates to true, a course-of-action is followed i.e., a statement or set-of-statements is executed. If the condition is false, it does nothing :