- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
How to optimize many SELECTs in a single table in MySQL?
To optimize many SELECTs, use it once and apply IN() to fetch multiple values. Let us first create a table −
mysql> create table DemoTable ( Id int, Name varchar(100), Age int ); Query OK, 0 rows affected (0.77 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable values(1,'Chris',23); Query OK, 1 row affected (0.39 sec) mysql> insert into DemoTable values(2,'David',21); Query OK, 1 row affected (0.56 sec) mysql> insert into DemoTable values(3,'Mike',24); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable values(4,'Robert',22); Query OK, 1 row affected (0.12 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable ;
This will produce the following output −
+------+--------+------+ | Id | Name | Age | +------+--------+------+ | 1 | Chris | 23 | | 2 | David | 21 | | 3 | Mike | 24 | | 4 | Robert | 22 | +------+--------+------+ 4 rows in set (0.00 sec)
Following is the query to optimize many SELECTs on a single table −
mysql> select Name from DemoTable where Age in(21,22,23);
This will produce the following output −
+--------+ | Name | +--------+ | Chris | | David | | Robert | +--------+ 3 rows in set (0.00 sec)
Advertisements
To Continue Learning Please Login
Login with Google