Tips for MySql queries

tips-mysql.sql

# When you need only 1 records, use Limit 1
SELECT * FROM default_users WHERE username='juliosguz' LIMIT 1;

# Try to not use undetermined functions like : RND(),NOW(),CURDATE() in your queries, because some times MySql disable cache for that
SELECT * FROM default_users WHERE birthday >= NOW(); # BAD
SELECT * FROM default_users ORDER BY RAND(); # BAD ++ !!!!
SELECT * FROM default_users WHERE birthday >= 1419032756; #GOOD , this value maybe you can get with time() function in php for example

# Avoid NULL fields in your tables

# Use MyISAM for reading table and InnoDB for writing tables
# For MyISAM , COUNT() works better but not INSERT/UPDATE/DELETE queries.
# For InnoDB , INSERT/UPDATE/DELETE queries works better.