Sort Keys
selected field or fields to sort records
A criteria that searches for fields that are not empty is called a "not null" criteria. This criteria is used to filter out records where a specific field does not have a null or empty value.
calculated field
select * from tablename
Any computer based database is composed of certain things in a certain order. The simplest part of a database is the field. Fields can contain pictures or text or sounds or instructions on what to do with other information in other fields. Fields are grouped into Records. Records are the total of all the information on a particular person or item. Records can be combined with other records then to build the database
A field that uniquely identifies a particular record in a table is called a primary key. The field or fields on which records are sorted is called the sort key.
A database contains records, which are collections of fields that hold specific pieces of information. Records are individual entries in a database, while fields are the individual data elements within those records.
Forces that act in a field are called field forces. These forces include gravity, electric fields, magnetic fields, and more. Field forces can affect objects within their respective fields without direct contact.
Records are distinguished from arrays by the fact that their number of fields is typically fixed, each field has a name, and that each field may have a different type.
You sort them, based on whichever order and field or fields you want.
Sort Key
An electromagnetic field is a physical field produced by electrically charged particles. It consists of electric fields and magnetic fields that interact with each other. When both electric and magnetic fields coexist, they form an electromagnetic field.