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MySQL

Tutorials and guides with interactive examples.

Quick Reference

MySQL Cheat SheetComplete syntax reference with interactive examples

Guides

MySQL DROP COLUMN: syntax and safetyALTER TABLE t DROP COLUMN c. MySQL has no IF EXISTS for columns, and dropping a column silently drops indexes that used it.
MySQL SUBSTRING: extract part of a stringSUBSTRING is 1-indexed, not 0-indexed. Position 0 returns an empty string, silently.
MySQL IF: function, statement, and IFNULLMySQL has two different IFs: an IF() function you use in queries, and an IF statement that only works inside stored programs.
MySQL DISTINCT: remove duplicate rowsSELECT DISTINCT removes duplicate rows, not duplicate values in one column. That distinction is where most DISTINCT bugs come from.
MySQL show usersList all MySQL users by querying the mysql.user table. No SHOW USERS command exists, but the query is straightforward.
MySQL JOINCombine rows from multiple tables with MySQL JOINs. Covers every JOIN type with examples.
MySQL SHOW DATABASESList all MySQL databases with SHOW DATABASES or query information_schema directly.
MySQL data typesMySQL's data types and when to use each one.
MySQL CREATE USERCreate MySQL users with the right host restrictions, passwords, and privileges.
MySQL Default Port and ConfigurationMySQL uses port 3306 by default. Here's how to check and change it.
SQL vs MySQLSQL is a language. MySQL is a database. Here's the difference.
MySQL DELETE: Complete GuideRemove data from MySQL tables safely and efficiently.
MySQL INSERT: Complete GuideAdd data to your MySQL tables the right way.
MySQL CREATE DATABASEEverything you need to know about creating MySQL databases.