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E. Removing a column:

To remove or drop a column in a table, ALTER TABLE command is used.
Syntax for removing a column:
ALTER TABLE <table-name> DROP
<column-name>;

For example,
ALTER TABLE student DROP (State);

The above command will drop State column from the student table.
Resultant table: student

Rollno Name Gender Marks DOB Mobile_no
1. Raj Kumar M 93 17-Nov-2000 NULL
2. Deep Singh M 98 22-Aug-1996 NULL
3. Ankit Sharma M 76 02-Feb-2000 NULL
4. Radhika Gupta F 78 03-Dec-1999 NULL
5. Payal Goel F 82 21-April-1998 NULL
6. Diksha Sharma F 80 17-Dec-1999 NULL
7. Gurpreet Kaur F 65 04-Jan-2000 NULL
8. Akshay Dureja M 90 05-May-1997 NULL
9. Shreya Anand F 70 08-Oct-1999 NULL
10. Prateek Mittal M 75 25-Dec-2000 NULL

11. DROP TABLE Command

Sometimes, we may need to physically remove a table which is not in use. DROP TABLE command
is used to remove/delete a table permanently. It should be kept in mind that we cannot drop a table
if it contains records. That is why all the rows of the table have to be deleted first and only then can
the table be dropped. This command will completely destroy the table structure.
Syntax for removing a table:
DROP TABLE <table-name>;

For example,

mysql>DROP TABLE student;

This command will permanently remove the table student from the database school.

12.14 SQL QUERY PROCESSING
Computer Science with Python–XII 12.28 screen. Retrieving information from the tables is done mainly using the SELECT command. The
After creating the database, the table is created and the data is stored in it. Now, it is time to
perform query processing on the already-created tables to retrieve and view the data on the

SQL SELECT statement is used to fetch data from one or more database tables. It is used to select
rows and columns from a database/relation.