MySQL Tutorial

A database system used with PHP.

Chapter Quiz Exercises
Course Topics
MySQL Intro MySQL SELECT MySQL SELECT DISTINCT MySQL WHERE MySQL ORDER BY MySQL AND, OR, NOT MySQL INSERT INTO MySQL NULL Values MySQL UPDATE MySQL DELETE MySQL LIMIT MySQL MIN() and MAX() MySQL COUNT(), AVG(), SUM() MySQL LIKE MySQL IN MySQL BETWEEN MySQL Aliases MySQL INNER JOIN MySQL LEFT JOIN MySQL RIGHT JOIN MySQL GROUP BY MySQL HAVING MySQL Create DB MySQL Drop DB MySQL Create Table MySQL Drop Table MySQL Alter Table MySQL Constraints MySQL Auto Increment MySQL Views

MySQL Constraints

MySQL Constraints

SQL constraints are used to specify rules for the data in a table.

Constraints are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the table.

Common Constraints:

  • NOT NULL - Ensures that a column cannot have a NULL value
  • UNIQUE - Ensures that all values in a column are different
  • PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Uniquely identifies each row in a table
  • FOREIGN KEY - Prevents actions that would destroy links between tables

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Topics
MySQL Intro MySQL SELECT MySQL SELECT DISTINCT MySQL WHERE MySQL ORDER BY MySQL AND, OR, NOT MySQL INSERT INTO MySQL NULL Values MySQL UPDATE MySQL DELETE MySQL LIMIT MySQL MIN() and MAX() MySQL COUNT(), AVG(), SUM() MySQL LIKE MySQL IN MySQL BETWEEN MySQL Aliases MySQL INNER JOIN MySQL LEFT JOIN MySQL RIGHT JOIN MySQL GROUP BY MySQL HAVING MySQL Create DB MySQL Drop DB MySQL Create Table MySQL Drop Table MySQL Alter Table MySQL Constraints MySQL Auto Increment MySQL Views