Learn SQL Database Programming

Understanding what data types to use

Data types define the type of value that can be stored in a column. To decide which data type a column should be, you need to know what kind of data will be stored in that column. In MySQL, there are three main data types: string, numeric, and datetime.

Each data type has different characteristics based on the amount of space it takes up, the kind of values that can be stored, whether the values can be indexed, and how the values are compared to each other. It's best to choose the most precise type to optimize storage.

For example, don't store the first name in a column with varchar(max), but instead store the first name in a column that would accommodate a long first name, such as varchar(20); this way, ...