do's and don'ts for writing mysql queries

Posted by nik on Stack Overflow See other posts from Stack Overflow or by nik
Published on 2010-04-23T07:49:42Z Indexed on 2010/04/23 7:53 UTC
Read the original article Hit count: 332

Filed under:

mysql

|

queries

|

database-design

|

dos-and-donts

|

php

One thing I always wonder while writing query is that am I writing most optimized query or not? I know certain things like:

1) using SELECT field1, filed2 instead of SELECT *

2) Giving proper indexes to the tables

but I am sure there are more things that should be kept in mind for writing queries, since most of the database can only grow more and optimal query will help gr8 in execution time, Can u share some tips and tricks on writing queries?

© Stack Overflow or respective owner

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>>… >>> More
mysql: Cannot load from mysql.proc. The table is probably corrupted

as seen on Server Fault - Search for 'Server Fault'
Mysql was started: /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 but when I'm trying to do something: ERROR 1548 (HY000) at line 1: Cannot… >>> More
Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

as seen on Server Fault - Search for 'Server Fault'
A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin. As far as I can tell, the only copy of MySQL… >>> More
mysql: Bind on unix socket: Permission denied

as seen on Server Fault - Search for 'Server Fault'
Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases… >>> More
MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

as seen on SQL Authority - Search for 'SQL Authority'
MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which… >>> More

Related posts about queries

SQL 2005 indexed queries slower than unindexed queries

as seen on Stack Overflow - Search for 'Stack Overflow'
Adding a seemingly perfectly index is having an unexpectedly adverse affect on a query performance... -- [Data] has a predictable structure and a simple clustered index of the primary key: ALTER TABLE [dbo].[Data] ADD PRIMARY KEY CLUSTERED ( [ID] ) -- My query, joins on itself looking for a certain… >>> More
Parameterized Queries /Without/ using queries.

as seen on Stack Overflow - Search for 'Stack Overflow'
I've got a bit of a poor situation here. I'm stuck working with commerce server, which doesn't do a whole lot of sanitization/parameterization. I'm trying to build up my queries to prevent SQL Injection, however some things like the searches / where clause on the search object need to be built up… >>> More
How to avoid this PDO exception: Cannot execute queries while other unbuffered queries are active

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I'd like to print a simple table in my page with 3 columns, building name, tags and architecture style. If I try to retrieve the list of building names and arch. styles there is no problem: SELECT buildings.name, arch_styles.style_name FROM buildings INNER JOIN buildings_arch_styles ON buildings… >>> More
When optimizing database queries, what exactly is the relationship between number of queries and siz

as seen on Stack Overflow - Search for 'Stack Overflow'
To optimize application speed, everyone always advises to minimize the number of queries an application makes to the database, consolidating them into fewer queries that retrieve more wherever possible. However, this also always comes with the caution that data transferred is still data transferred… >>> More
FirePHP not returning ajax request queries, yet returns normal page load queries

as seen on Stack Overflow - Search for 'Stack Overflow'
I am using firePHP(Zend profiler) on on FF 3.6.3(firephp addon installed) and it returns queries, when I do a normal page load. Ajax requests, however, are not returning the proper queries. I am using Prototype 1.6.0.2 for ajax requests. Is there something I am missing? Most of the write-ups seem… >>> More