The ppt is part of the YouTube Video on SQL. https://youtu.be/1oL9o3SZ1bA The SQL Video teaches you and also shows you example of the usage of ALTER TABLE, SELECT DISTINCT and WHERE commands in SQL command line.

1. SQL
ALTER TABLE,
SELECT DISTINCT &
WHERE VIDEO

2. ALTER TABLE
• 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.
• ADD COLUMN
• DROP COLUMN
• ALTER/MODIFY COLUMN

3. ADD
COLUM
N
• ALTER TABLE table_name ADD column_name
datatype;
Syntax:
• ALTER TABLE Customers ADD Email
varchar(255);
Example:

4. DROP
COLUM
N
• ALTER TABLE table_name
DROP COLUMN
column_name;
Syntax:
• ALTER TABLE Customers
DROP COLUMN Email;
Example:

5. ALTER
COLUM
N
• ALTER TABLE table_name
ALTER COLUMN
column_name datatype;
Syntax:
• ALTER TABLE Persons
ALTER COLUMN DateOfBirth
year;
Example:

6. SELECT DISTINCT
• The SELECT DISTINCT statement is used to return only distinct
(different) values.
• Inside a table, a column often contains many duplicate values;
and sometimes you only want to list the different (distinct)
values.
Syntax:
SELECT DISTINCT column1, column2, ... FROM
table_name;
Example:

7. WHERE
• The WHERE clause is used to filter records.
• It is used to extract only those records that fulfill a specified
condition.
Syntax:
SELECT column1, column2, ... FROM table_name
WHERE condition;
Example:
SELECT * FROM Customers WHERE Country='Mexico';
SELECT * FROM Customers WHERE CustomerID=1;