What are the commonly used field types and what characteristics do they have?

In the case of analysis, it is generally quantitative, ordinal, and categorical variables.

Quantitative, such as age.

Orderly, such as academic qualifications, have an order relationship, but there are no quantitative differences.

The categorical variable is gender, and there is no quantitative relationship and no order.

Commonly used field types can be roughly divided into three categories: numeric types, string types, and date and time types.

MySQL supports a large number of field types, many of which are commonly used. Numeric types can be divided into three subcategories: integer, floating-point, and fixed-point. Integers are often used, such as tinyint, int, and bigint.

By default, it is signed, if you only need to store unsigned values, you can add an unsigned attribute. There are two main floating-point types: float and double, and the floating-point type stores the approximate value in the database. There is a decimal fixed-point field type, which is mainly used to store the decimal of the starter with accuracy requirements.

The string types char and varchar are the most commonly used. MySQL supports the following types of dates and times: year, time, date, datetime, and timestamp.

Summary. Hello, dear. What are the four basic properties of a field?

Static, instance, constant, and read-only fields. The above four types are the basic attributes of a field. What are the four basic properties of a field?

Static, instance, constant, and read-only fields. The above four types are the basic attributes of a field.

Hello, dear. There are four basic properties of a field: static field, instance field, constant field, and read-only field.

The above four types are the basic attributes of a field. There are four basic attributes of a field: static field, instance field, constant field, and read-only base field.

The above 4 are the basic starvation attributes of the field.

Each field must have a name, called a "field name", which identifies the field in the table. The field name should generally be the same or similar to the attribute name of the entity to which it corresponds. For example, the field name in the "Student ID" column of the student information table can be "Student ID" or "SNO" or "Rolling Travel XH" or "Xuehao".

The naming rules for field names are the same as those for memory variables, and Chinese vfp allows the use of Chinese characters as field names.