MySQL Tutorials

MySQL | Data Types | Conditions | Queries | Relationships | Scripts

MySQL is a database server that generates databases over a network. A database is a file that stores data in tables. A table represents an object. An object is defined in columns and rows. Columns represent the names of an object's attributes. Rows represent the values.

MySQL is a RDBMS (Relational Database Management System) that uses SQL (Structured Query Language). SQL is a standard computer language for accessing a RDBMS. SQL is cross-platform and can used in a variety of applications. Microsoft Access is a RDBMS that also uses SQL. Access generates on a local computer, not over a network.

PHP can manage and send SQL queries to the MySQL server. Tutorials for coding SQL within PHP scripts are on the Scripts page.


Databases, tables, and columns have a similar naming convention...

• start with a letter
• letters, numbers, and underscores only
• no more than 18 characters
• no spaces unless declared in  [ ] square brackets
• no SQL keywords
• lowercase recomended

SQL keywords are coded as UPPERCASE (recommended). A new table is declared by creating column names with data types. Data type values are declared in ( ) parenthesis. The  ,  comma separates column names. The  ;  semicolon declares the end of an SQL statement. This is an example of an SQL statement that creates a table...

CREATE TABLE table1 (
column1 INT AUTO_INCREMENT,
PRIMARY KEY(column1),
column2 VARCHAR(30),
column3 VARCHAR(30)
);

The PRIMARY KEY declares one of the columns as the id column to identify rows, and is usually defined with the AUTO_INCREMENT attribute.  AUTO_INCREMENT increases the id column by 1 each time a new row is added, starting with 0 by default. The PRIMARY KEY column is usually declared with a numeric data type, such as INT. These are examples of SQL statements...

Values can be selected from a column in a table...

SELECT column1 FROM table1;

Values can be selected from multiple columns in a table...

SELECT column1, column2 FROM table1;

Values can be selected from multiple columns in multiple tables. The  .  is the concatenation operator...

SELECT table1.column1, table2.column1 FROM table1, table2;

Tutorials for installation and configuration of MySQL are on the Install page.