Learn MySQL Important Queries – Part 2

Hello friends, I’m going to discuss the second part Learn MySQL Important Queries,  In the previous part, we learned basic and essential part of MySQL queries. In this part, we’ll learn about some advanced query that will help you in RDBMS (Relational Database Management System).

ALTER TABLE

Add Column

The syntax to add a new column to an existing table is:

ALTER TABLE Student ADD COLUMN LastName Varchar(50);

You can also define where the column is going to place.

ALTER TABLE Student ADD COLUMN LastName Varchar(50) AFTER RollNo;

Delete Column

The syntax to delete an existing column is:

Any data contained in a dropped column will be deleted as well.

ALTER TABLE Students DROP COLUMN photo;

Rename Table

To Rename the entire table, the syntax is:

ALTER TABLE Students RENAME TO Student_details;

Operators

MySQL queries can benefit from the use of several operators and clauses.

SELECT * FROM Studen WHERE name LIKE '%T%' AND gender LIKE 'Female';

SELECT * FROM Student WHERE (name LIKE 'Kumar ' AND gender LIKE 'male') OR
                            (Name LIKE 'Rahul' AND gender LIKE 'male');

Distinct

We use DISTINCT to avoid duplicate value

SELECT DISTINCT name FROM student ORDER BY name;

Count 

The COUNT() function is used for count the rows.

SELECT COUNT(*) FROM student;

Also View: –

Learn MySQL Important Queries – Part 1

Extract Data in Excel From MySQL database using PHP in Specific Date Range

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